I'm an electrical engineering junior and this video made me have to back up and take a look at some transmission line material. He is pretty accurate in all he said without making it too technical. Very nice! I wish I had more of an opportunity to learn these things from experience as opposed to through differential equations...
@@blaydv2242 Not an electrical engineering major. But, a lot of the internet uses optical cable runs. Deep sea internet cables are optical, however they do go so far they need repeaters.
When his schedule is so tight that he can't afford to do a retake of that section but they couldn't cut out him taking the call because the ringtone wouldn't make any sense
mohawkade Undersea cables are invariably optical, but can run spans so long that undersea repeaters are still needed. High voltage DC wires run alongside the optical cable to power said repeaters and splitters.
Zahid. 1st. The Samsung Exynos CPU is one of the best CPU's for a mobile phone 2nd. don't compare a iPhone 6s with a fail, compare it with a S7 but to be honest, the OnePlus 3 is a better way to go 3rd. Without Samsung, even more companies woudln't exist that godlike, Samsung has 2 manufacture "houses" for CPU's, GPU's (should help Nvidia) etc. etc. 4th. please don't pour so much of your sheeple juice 5th. get out with that motherfucking PCMR profilepic if you're a sheeple 6th. thanks
For digital, the signal is either on or off so length does not matter until the cable gets so long that the signal drops out altogether. For analog, the signal can be affected by cable length or outside interference so cable length and shielding matters more.
I'm sure everyone has at least once in their liftime run a ridiculously long ethernet cable through multiple floors, windows and rooms to have that sweet wired connection. Hell, I even ran one from one building to another for a while.
I run a portable church campus and we run all our inputs into a netgear router and send it all through CAT6 for 150 foot from stage to the soundboard. All 32 channels. Also know a buddy that just installed CAT6 into his parents home with a control center that converts it to hdmi for future proof solution to video and audio transfer through a house with 10 TVs. It’s versatile stuff
I several long run cables. They go down through a hole in the floor and run across the basement and up through another hole at it's destination. There is also one cable that goes upstairs through a hole.
Cat 5e can have a run of 100 meters. The only critical aspect is the how the bends are. If you bend a network cable too tightly in a corner, it will not work as intended.
Important addition to those copper cables that Linus completely forgot to mention: If you use them to power something (i.e. usb) the actual rated distance may differ from the data distance. For data all that matters is that the signal at the other end is above a minimum intensity in order to identify a 1 from a 0. With power however, you need to have a minimum amount of it arriving. As power, or data for that matter, travels through the copper cable some of it is 'spent' overcoming the resistance of the cable itself meaning the voltage at the end will be lower than at the start. So while at the 'start' the cable might be fed with 5.0v, at the end that might have dropped to 4.5v or even less. Some equipment might work fine with lower voltages, but some outright won't work or won't work properly. It's also important to realize that not every USB cable is created equally. The 'usb power' wires in a usb cable can vary in thickness and thus resistance. A usb cable with ticker power wires, and thus lower resistance, will drop in voltage less over distance than a (usually cheaper because less copper is used) cable with thinner wires. It's also not just a case of "well just feed more voltage into it then to overcome the distance". If you feed 12v into a usb cable that's 10m long and it's dropped down to 5v that means those 'lost' 7 watts (assuming 1 Ampere current) are literally heating your cable up. It could melt or, worse still, catch on fire.
:) Cos just one of those power supplies can provide only 125W at max, you need an internal desktop PSU in order to have more, but that would be adding more heat to the system.
The only USB cables that I can fast charge my phone with are all less than 10 inches long. The longest cables I've used tend to make my phone display "charging slowly". It does matter.
Same thing with charging. At 5v, USB charging really can slow at 10 feet (an the cable is easier to damage) It's almost better to use a regular extension cord vs long USB cable. Of course, with newer fast chargers negotiating up to 20v, that may not matter. But does the longer length or more change of a damaged bit of cable hamper the negotiation. Defaulting it to 5v
Thank you, you have helped me learn a lot about tech over the past few months. It has even got me sharing your vids with friends and talking about the stuff I have learned here with co-workers. I appreciate all the work you have put into your videos.
I have been told that many prefer a long, thick cable with a massive plug on the end to open up and expand the data stream over a short, thin one with a small plug. Or so I have been told.
Good final destination, but what you don't understand is all stuff on copper is analog, when wire is too long using a digital modulated signal you end up with a high error rate, with no FEC (forward error correction), you get fractals or artifacts. Plastic Fiber suffers not from attenuation, but rather from inter symbol interference due to the different paths through the plastic because the structure is not as uniform as in a glass predictable crystal structure because of how the glass is grown. The plastic causes light scattering smearing the signal causing errors.
I've been looking at systems where increasing from 0.5m to 1m cables creates a significant (>1%) increase in latency for network traffic so it's not always about signal integrity.
Signal degradation is rough. I had the most messed up problem with a long usb cable extender, and it wasn't a matter of "it either works or it doesn't". The USB cable was "mostly" working but my mouse would occasionally freeze for a second and then resume. Mostly harmless, but for a gamer this won't work. Also the lights weren't syncing on my peripheral devices. It was hours and hours of troubleshooting before I figured out it was the usb cable extender. I didn't understand about signal degradation in long cords. It's really, really frustrating.
Thanks Linus! In the market for purchasing HDMI cables at 30' or 40' long and needed to know if a repeater is necessary. I thought 25' was the safe limit for HDMI... although same are saying that is true depending on the build quality, at which point is a matter of how or miss, or x out y cables are likely to have issues at the given length.
The only UA-camr who make serious diverse differences..most of the rest do just phone comparisons but this guy's goes beyond to computers and their peripherals ...u the man keep it up
Can you explain why Ethernet cables are so much more efficient at transferring data over long distances? Could you also talk about this problem in relation to internet/cable service? :)
How long hdmi 1.4 cable will be workable ? I want to keep a good 10feet distance from my 60 inch full hd t.v. while using my cheap 12inch laptop asus eebook 12. Please answer if u know or have any idea.
considering what Linus said about the maximum lengths for those cables, I'm pretty happy the only long cable I need is for ethernet, everything else being under 1m long
There are a number of technical errors in this video. First, 1:29 you mean resistance or attenuation, not impedance. The characteristic impedance of a cable doesn't change with distance, but signal attenuation does. This is due to dielectric loss as well as ordinary resistance; worse, dielectric loss increases at higher frequencies, which is why higher bandwidth signals (eg USB 3 vs USB 2) are more sensitive to length than lower bandwidth signals. 3:30 it's not reflections that cause the problem, it's dielectric loss, and reflections are caused by impedance mismatches (usually due to crappy cable and/or connectors). Delay has nothing to do with it, except insofar as delay affects how reflections degrade a signal. A properly designed impedance-controlled transmission line (which these sorts of cables are) should have minimal reflections, can have wide bandwidth and can be much longer than the highest frequency component it carries. Example: the actual cable of CATV has a bandwidth of around 800 MHz or so and can carry multiple gigabit digital signals in DOCSIS 3, yet CATV cable runs are commonly way longer than anything you'd find in a single household (and can be miles and miles with appropriate regeneration). The difference is in the design of the protocol, the quality of cable and launch power amongst others. Aside from dielectric loss, there are no analogue-domain limitations in principle on the length of a cable, provided it is properly impedance matched. (Example: SATA and SAS are the same protocols and use the same sort of cabling, but SAS has a higher voltage drive so it can reach further.) There's one exception to that: some protocols are designed in such a way that excess latency (delay or response to a message) can break them. GSM phones, for example, have an absolute limit of 35km, regardless of signal strength or boosters. 3:40 Reflections don't cause damage except in high power RF transmitters because there's just not enough energy in them to do any damage. They will, however, degrade signal integrity which will make the signal unusable.
Linus says impedance, not characteristic impedance, so he's right in that regard. Dielectric loss causes the signal to not reach the other end, but we're talking about a tighter limit when the signal reaches the other end intact-the device needs to ACK back fast enough. USB is half-duplex but apparently requires a short ACK time. Impedance matching solves the amplitude of reflection so that the host can send another bit faster because it does not have to wait for the reflection to settle nearly as long, but the ACK requirement still limits the delay. Linus is half-right in that reflection can matter, but he fails to point out another limit when reflection is limited via matching circuits. You're right that "the difference is in the design of the protocol, the quality of cable and launch power amongst others". Depending on the combination of these factors a standard may hit one limit before another. The USB committee thinks that reflection can damage the circuit though www.usb.org/developers/usbfaq/#cab1
> Linus says impedance, not characteristic impedance, so he's right in that regard. Not really. Impedance and attenuation are not the same things. Attenuation is a combination of frequency-dependent dielectric parallel loss and resistive (ie non-reactive) series loss, both resulting in heat dissipation in the cable. Resistive loss gets worse with frequency because of the skin effect, but that's different again from dielectric absorption. As you say, dielectric loss causes the signal not to reach the other end of the cable because it's all gone as heat, and there's nothing you can do about that except get lower loss cable or amplify the source driver. Impedance (characteristic or lumped), OTOH, is about power transfer. You can transfer all developed power at any impedance (within reason) provided source and sink are matched with the effective impedance of the transmission line. I'm simplifying a bit: you can't easily compensate for impedance mismatches in a transmission line with a matching network, however you can use RF traps or stubs as notch filters to filter out specific frequencies, but that doesn't work with baseband signals. > Impedance matching solves the amplitude of reflection so that the host can send another bit faster because it does not have to wait for the reflection to settle nearly as long As you say, impedance mismatches result in reflections that reduce the power delivered to the load - but the energy hasn't gone away as with attenuation, it's merely not going where it should. Reflections also degrade signal integrity as well as reducing power available at the load. In a properly impedance-matched, load-terminated system, you don't need to wait for anything to settle because all transmitted power is fully absorbed by the receiver's terminator and there is no particular limit, save for attenuation, on the rate at which you can transmit bits down a properly matched transmission line. Source-terminated systems achieve the same ends but depend on constructive interference from reflected wavefronts to build up full signal magnitude (c.f. parallel PCI reflected-wave switching). It's been too long a go since I studied source termination since none of the designs I've worked on use it and I can't remember what happens when the bit rate approaches the return-reflection period or what the implications for USB SI (as opposed to ACK times) would be. > when the signal reaches the other end intact-the device needs to ACK back fast enough. USB is half-duplex but apparently requires a short ACK time. True, but this is a protocol matter, not a property of the cable and the time scales are completely different. Even at a pessimistic 50% c, signals still go about 6 inches per nanosecond or 20 ns per 10' cable. From memory, the polling period of USB 2 high-speed is 125 µs which is about 6000 times slower than the propagation delay in a 10' cable and 600 times slower than a 100' cable (if you could build a lossless cable), which is still plenty of time to return the ACK. The cables FAQ you linked talks about a budget of 26ns cable delay for the sake of signal integrity in badly terminated transmission lines, not because of ACK timeouts. I'm not sure what the exact timeout is on USB. One source I read suggested 50 ms, but that might only be for lower speed USB devices, and that's 6 orders of magnitude slower than propagation delay. > Linus is half-right in that reflection can matter Yes, but for the wrong reasons, hence my OP. > The USB committee thinks that reflection can damage the circuit though They're suggesting that, under the right circumstances, there can be enough constructive reflection interference as to damage the driver. Assuming adequate ESD protection, that seems unlikely because I don't see constructive interference amounting to kilovolts. Besides, if I remember how source termination works correctly, the outbound wavefront is 50% magnitude and the reflection builds up to 100% magnitude. If USB is source terminated and setting aside inductive effects, it shouldn't be possible to get > Voh.
Thanks for the reply. I'm in computer engineering and this conversation again proves how little do I know outside of my own comfort zone. One more question though: why does the USB committee have a tighter limit on low-speed cables (18ns) than high-speed cables (26ns)? This doesn't quite make sense to me and I thought the only reason is the speed the device replies, but as you said it shouldn't matter here. Do they assume low-speed cables are crappier?
> I'm in computer engineering Nominally, I'm a computer scientist but I've ended up doing mostly electronic engineering in my professional career, plus I have a recently-acquired interest in software-defined radio. Just one of those things, I guess. > One more question though: why does the USB committee have a tighter limit on low-speed cables (18ns) than high-speed cables (26ns)? Good question. I'd have to closely examine the USB standard to answer that properly, but I don't have a copy of it to hand. I'm not used to allowing for ringing and poor SI; I'm much more accustomed to ensuring that there is good SI and as little ringing and ground-bounce as possible. IOW, design the protocol to avoid bad conditions, that way you don't have to compensate for them. USB is a truly awful protocol (I built a USB HID for a flight simulator), but it's cheap and we're stuck with it. > This doesn't quite make sense to me Nor to me. Normally, propagation delay is a sufficiently small proportion of processing latency that it is largely negligible. For example, 25 ns is 2.5 cycles of a 100 MHz clock, and even that is fairly slow by modern standards. You can do bugger all in 2 cycles, which illustrates why processing delay dominates propagation delay. > Do they assume low-speed cables are crappier? That would be a reasonable assumption ;) I am sure that cheap, low-speed devices have terrible electrical/SI characteristics. USB is a cheap protocol designed for low cost devices. So is PCI Express, albeit on a slightly faster and smaller scale. Were it otherwise, it wouldn't gain sufficient market up-take.
One thing that should be mentioned when talking about electrical cables and wires. When you use cables and wires that are longer then you need and you create a tangled mess you are probability creating impedance along with your mess. Of course if you are one of those people who take care of the mess problem by coiling your excess wire or cable are of course building impedance coils. This can happen even with shielded cables depending on how much electromagnetic bleed out your cables have. Speaker and power wires are especially susceptible to this. I know that I'm stating the obvious but a lot of people seem not to think of this considering some of the power and speaker runs that I've seen.
that face of that woman at "longer doesn't necessarily mean better" is just priceless! Nice going finding that on that service you guys used to put out there all the time lol!
I'm sure no one else can match my brilliance when I make a fantastic quip that has never been heard before. "Size isn't important. It's the motion of the waves."
Great video. I do fiber optic splicing and fusing occasionally at my job and it is very tedious work. The machine test for DB loss in the fuse. The worst I accept is a .02 DB loss.
It's a combination of length and thickness. You also need to practice your technique. You can't just ram it in. Make sure it's aligned correctly or you could damage the socket
A big thank you for the simplicity of explanation of such matters. This particular video was a big help with a recent upgrade I am working on, thanks again.
Working with building fiber optic networks and i can safely say that you can get cables up to 6 kilometers without any delay nor data loss (easily longer also, issue is that you usually cant buy longer cables then that without putting a weld somewhere) The onlything u really need to care about is to not bend it to tight since it will make you loose signal strength. The reason you cant have long length on some cables is due to the fact they use cheap materials or simply have to big cores. nowdays you use SM (Single mode) instead of MM (multimode) which have increase the lengths dramatically. This is the main reason we can now get fiber to home not just companies. The smaller the core the less signal loss
Note: Since you are using specs in the first place: 100m solid core (as a replacement for the permanent/horizontal cable?) is out of specs, it might work or it won't or something in between for people who like troubleshooting. For regular patch cables (AWG24, stranded) the max length would be 85m.
These educational videos of yours are my favorite, I love learning about technology like this, when I think of you, these are the videos I think of. I didn’t even know these weren’t on your main channel! Haha
i think also if your cable is long enough to have enough resistance to cause a voltage drop to the point where a logic high is no longer reached, then there go your ones and zeros because all youll get are zeros
My gf dumped me because my length wasn't at least 20ft. 20ft!! WHO NEEDS ALL OF THAT? I can hook up my HDMI from the cable box to the tv... what more does she need?
Well, having a really long cable also affects the signal speed a lot, which can potentially give noticeable delays. The signal in an optical fiber travels at the speed of light in vacuum divided by the refractive index, usually about 1.5 for glass, meaning that it's ~33 % slower than in vacuum. For electrical cables, both digital and analog, the signal speed is probably less. For the cabling used at home, this probably doesn't matter much, but it IS measurable and scales with cable length.
this video is still so relevant today. Yesterday, my friend asked me the does HDMI 2.1 cable length matters... I request the length since in most cases it does not matter for in-home us. But he said he saw some "post" said matel cable can not be longer than 5 meters... At the moment I am so confused that does "non-metal" HDMI is a thing....
i also… recently bought a fibre optic, HDMI cable; and they are really good too. Especially for very long lengths. I’m using this fibre optic cable… from my pioneer receiver, into the tv. Friday 3rd February 2023. U.K. Southampton
Linus, the light in a fiber optic cable does not diminish as a regular point source of light would. Attenuation in a fiber optic cable happens by a completely different property and has more to do with the refractive indices of the fiber and the cladding around it.
PC Master Race I think a view only counts if you watch more than a % of the video, while a like is a click based count, if I like the video as soon as I start watching it, the like counts, the view doesn't (yet)
Donald it doesn't work that way. It only registers one after 15s of any video to prevent the viability of clickbots. They used to be a big problem until the limit was added before adding a view count.
It register after a few seconds.... Back when UA-cam launched it was click based. But now it's duration based. I was just making a joke guys, not make it serious..... Have a great day
also depend on what your using the cable for... if your using it for DATA transfer then it can matter, but generally the shorter the better as for things like USB charging, of say phones, speakers etc the length on the cable is less of an issue.
Tbh it's one of the first things I think about ahah. I'm extremely/analy clean and organised. Cable organisation and the cleanliness of the set up is very important
You should note that resolution matters for HDMI. My installation guys connected a 50ft HDMI cable from my 4K player to the projector, and I noticed some black fuzzies on the screen that I thought were from the encoder or something and came with the territory on 4k. When we got a different 4K player those fuzzies got even worse... That's when I researched that 4K is supposed to use shorter cable runs so I put in a 25ft cable and everything was crystal clear. On USB (and firewire) things like a keyboard you won't notice a difference as you approach the maximum cable length. However, when I had maximum length cables for the medium (3m like you said) there were brief gaps in communication between my interfaces and Pro Tools that result in the recording being stopped. I changed to a shorter cable length and this problem went away. Also, some optical formats like MADI are getting up to thousands of meters in length. Those cables are getting up to thousands of dollars in cost too though.
the only time you get cross talk, is when you run your low voltage to close to your line voltage. as for fiber optic they can run fiber cable under ground for quite a few miles depending on the diameter of the cable, but if your more concerned about voltage drop. then use a thicker wire
A lot of factors matter in the design of a cable... Length and gauge(diameter of cable) will affect the total resistance of the cable. Note also the material but most use copper. The relation between the total resistance of the cable and the voltage will affect the amount of current in the cable wich will determine the intensity of the magnetic field around the cable, wich can act as an inductor wich can filter out some signals and cause noise and interferance. While designing a cable, we have to take in consideration the material and the gauge of the cable and also set limits in length depending on how the signal works and the voltage at witch it is sent, ect...
1:27 you actually want impedance to be matched in many cases; the word that should go there is "resistance". Also of note, many cheap cables will increase the outer jacket size, but still use a crappy (or even crappier!) gauge wire, which doesn't do you any good, even if the cable is thicker.
The nature of digital is that the information could be transmitted perfectly. Error correction could catch any bit flips. Although the error rate of a cable transmission is negligible. But if the error rate becomes too much, you have to resort to dropping the bit rate. The reason your Skype is noisy is NOT because digital isn't perfect but because it's real time so it has to make do with the errors to remain real time
TL;DW Analog Cables: Shorter and thicker cables are better. Digital Cables:- HDMI: 15 metres USB:- 2.0: 5 metres 3.0: 3 metres 3.2 Gen 2: 1 metre (Can be extended with an active cable or a repeater) Ethernet cables: 100 metres Optical cables:- Toslink: 10 metres Thunderbolt 2: 60 metres Thunderbolt 3:- No active cable: 0.5 metres Active cable: 1-2 metres
Shorter is better? Oh thank god. I thought I had something to worry about.
lmao
Lmao
same
Lmao
lmao
“You hear that little buddy?”
Oh shit that got me bhahahaha
It still doesn't matter if it doesn't last long in bed
Yea
@@lemonheep you don't need cables to last long in bed....
Not in my bed 😏
@@weeb69 Damn, that must be some really rough bdsm
The length of your “cable” doesn’t really matter if you have nothing to plug it into
Dont worry I'll buy you a port😆😜
Just roasted the whole comment section
I know you're not talking about me because I still have most of my mining rig from 2017, giving me about 30 ports in total
true
I feel personally attacked
Fine, I won't get the 50ft HDMI cable that's priced lower than the 6ft one.
Well we are not saying that.... dont go that far
@@viperlife914 r/whooosh
@@OfficialProject420 that’s not really a whooosh but I guess it works
@@OfficialProject420 not really a whoosh
@@OfficialProject420 r/woooosh
"longer doesn't necessarily means better"
hmmm....
memo boy that’s what she said! ,,,, Oh...
ringoaikocascade She wants a bigger stick.
It's how you use it that matters
memo boy r/hmmm
“Get your mind out of the gutter!” -Linus
I'm an electrical engineering junior and this video made me have to back up and take a look at some transmission line material. He is pretty accurate in all he said without making it too technical. Very nice! I wish I had more of an opportunity to learn these things from experience as opposed to through differential equations...
Ahh thats only the first year, to scare the wannibies off the course, year 2 you will be learning real stuff).
What things use optical cables?
How has it been going?
@@blaydv2242 Not an electrical engineering major. But, a lot of the internet uses optical cable runs. Deep sea internet cables are optical, however they do go so far they need repeaters.
Foget Maffs... use Hammer... SMASH!... UG!
0:49
Just when you thought Linus was making a joke call
but no, he wasn't
I thought he was going to use it for sponsorship 😂
When his schedule is so tight that he can't afford to do a retake of that section but they couldn't cut out him taking the call because the ringtone wouldn't make any sense
@@bumblethebee761 too 😂
I thought he ment “wireless”
Cause he is talking about wire
@@bumblethebee761 lol same was just about to skip 30 seconds ahead.
0:45 i've watched so much youtube that I assumed that phone call was going to be an advertisement
length doesn't matter. girth does.
Jake Conner 😂😂
Jake Conner yay for chodes
my nickname in high school was tuna can
that's exactly what she said
they call me hydraulic press because i always crush the pussy
This brings up a question, what about deep sea internet cables crossing oceans, connecting continents together to the world wide web?
mohawkade lol
mohawkade Undersea cables are invariably optical, but can run spans so long that undersea repeaters are still needed. High voltage DC wires run alongside the optical cable to power said repeaters and splitters.
WarmSoftKitty you're joking, right
WarmSoftKitty all you need to do is Google "undersea internet cable".
en.wikipedia.org/wiki/Submarine_communications_cable. Do your research before you blow up on someone.
almost a year later and Linus is still shitting on WireWorld.
well that stuff has to be the biggest rip-off in consumer tech so far
Medicate I'm afraid Apple beat them to it.
The moment he mentioned wires I was totally expecting that shit. Being realistic, wouldn't you still be mad? I mean, he payed the 1k xD
Zahid Shabir Samsung manufacture processors for apple
Zahid.
1st. The Samsung Exynos CPU is one of the best CPU's for a mobile phone
2nd. don't compare a iPhone 6s with a fail, compare it with a S7 but to be honest, the OnePlus 3 is a better way to go
3rd. Without Samsung, even more companies woudln't exist that godlike, Samsung has 2 manufacture "houses" for CPU's, GPU's (should help Nvidia) etc. etc.
4th. please don't pour so much of your sheeple juice
5th. get out with that motherfucking PCMR profilepic if you're a sheeple
6th. thanks
It’s hard to find helpful comments
Wow finally a comment that's not bs lol
maybe you are hearing too much crosstalk? welcome to the wonderful world of copper cables
@@godsinbox if u were on reddit, id give you a silver.
For digital, the signal is either on or off so length does not matter until the cable gets so long that the signal drops out altogether. For analog, the signal can be affected by cable length or outside interference so cable length and shielding matters more.
Size always matters... that's what he said.
This Motherfocka wait.... what?
Does anybody else read it with Pink Guys voice?
Paperclown Good for you. I know some day I will look this stuff up for actual reference and will hate the jokes. Love them AND hate them.
toe
This Motherfocka he bro? ummmm, oh yeah it's 2017 nevermind
I came here to learn about cables but my self-esteem got a boost while learning.
Prepare yourself for comments from people who only clicked on this video to make a dirty joke
The Con Oh yeah yeah
I don't understand, why would someone make a dirty joke?
@@phynx2006, why not lol
Is there any other reason to watch this?
Two comments above yours just did that.
can we actually get benchmarks of transfer speed and charging speed for different cable lenghts over on LinusTechTips?
I'm pretty sure it's about fidelity at that point
it isn't the length of the cable that matters, but how you use it
I'm sure everyone has at least once in their liftime run a ridiculously long ethernet cable through multiple floors, windows and rooms to have that sweet wired connection. Hell, I even ran one from one building to another for a while.
Peasant of Pontus 😂
mine currently runs through my vent from upstairs to my room downstairs
I run a portable church campus and we run all our inputs into a netgear router and send it all through CAT6 for 150 foot from stage to the soundboard. All 32 channels. Also know a buddy that just installed CAT6 into his parents home with a control center that converts it to hdmi for future proof solution to video and audio transfer through a house with 10 TVs. It’s versatile stuff
I several long run cables. They go down through a hole in the floor and run across the basement and up through another hole at it's destination. There is also one cable that goes upstairs through a hole.
Cat 5e can have a run of 100 meters. The only critical aspect is the how the bends are. If you bend a network cable too tightly in a corner, it will not work as intended.
but the amazing thing is that this video starts from 0:00 and ends at 6:48
wow
THANK YOU saved my time
PC Master Race Except it ends at 5:29
PC Master Race Thank you for this amazing comment. I had no clue when the video ended.
Thanks guys. HOPE I HELPED.
Lol
Me: interesting.. i might watch it
Comment section
*bunch of dirty jokes*
I Liked Ur comment so u have 69 likes
Razer called. They want Project Valerie back
Important addition to those copper cables that Linus completely forgot to mention:
If you use them to power something (i.e. usb) the actual rated distance may differ from the data distance.
For data all that matters is that the signal at the other end is above a minimum intensity in order to identify a 1 from a 0.
With power however, you need to have a minimum amount of it arriving.
As power, or data for that matter, travels through the copper cable some of it is 'spent' overcoming the resistance of the cable itself meaning the voltage at the end will be lower than at the start.
So while at the 'start' the cable might be fed with 5.0v, at the end that might have dropped to 4.5v or even less.
Some equipment might work fine with lower voltages, but some outright won't work or won't work properly.
It's also important to realize that not every USB cable is created equally. The 'usb power' wires in a usb cable can vary in thickness and thus resistance.
A usb cable with ticker power wires, and thus lower resistance, will drop in voltage less over distance than a (usually cheaper because less copper is used) cable with thinner wires.
It's also not just a case of "well just feed more voltage into it then to overcome the distance". If you feed 12v into a usb cable that's 10m long and it's dropped down to 5v that means those 'lost' 7 watts (assuming 1 Ampere current) are literally heating your cable up. It could melt or, worse still, catch on fire.
But I thought size always mattered.
Kevin Sam "A to B" (lenny face)
Ah, AlternateHistoryHub (the avatar).
Nope. I've seen long ones with poor performance 😩
:) This isn't about size but about length. D
:) Cos just one of those power supplies can provide only 125W at max, you need an internal desktop PSU in order to have more, but that would be adding more heat to the system.
Person: HDMI cables
Auto captions: HDMI *Tables*
I have a 40 ft USB extention cable I use to charge my phone. lmfao
GLACIAL tf
There will be no bit reflections because it is only transmitting power not data
But you’re all forgetting about the increase in electrical resistance in ohms created by a thinner, or longer cable
The only USB cables that I can fast charge my phone with are all less than 10 inches long. The longest cables I've used tend to make my phone display "charging slowly". It does matter.
@@noxious89123 use a thicker usb cable mine is 5 meters long and my phone still charges Quick Charge 4.0
Linus: Lenght does effect performance
Me: *Looks at my 10 meter long ethernet cable that I just use to plug my pc 1 meter away in the ethernet port*
Meanwhile i use 30 meter cable to hook up my pc less than 10 meter away from the router
the hit reg of games were better when I used 1 meter cable instead of 15 meters
I’m
@@tiggerwigger I’m
@@BooneTheKing I’m
replace the word "cable" in the title of the video
redninja960 Data speed
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"When Does Death Ray Canon Length Matter?"
When does ass cancer length matter?
Same thing with charging. At 5v, USB charging really can slow at 10 feet (an the cable is easier to damage)
It's almost better to use a regular extension cord vs long USB cable. Of course, with newer fast chargers negotiating up to 20v, that may not matter. But does the longer length or more change of a damaged bit of cable hamper the negotiation. Defaulting it to 5v
Thank you, you have helped me learn a lot about tech over the past few months. It has even got me sharing your vids with friends and talking about the stuff I have learned here with co-workers. I appreciate all the work you have put into your videos.
I have been told that many prefer a long, thick cable with a massive plug on the end to open up and expand the data stream over a short, thin one with a small plug. Or so I have been told.
I was rewiring my cable management on my desk when this video popped up in my feed lol!
Deon Spates LOOOOOL XD
Good final destination, but what you don't understand is all stuff on copper is analog, when wire is too long using a digital modulated signal you end up with a high error rate, with no FEC (forward error correction), you get fractals or artifacts. Plastic Fiber suffers not from attenuation, but rather from inter symbol interference due to the different paths through the plastic because the structure is not as uniform as in a glass predictable crystal structure because of how the glass is grown. The plastic causes light scattering smearing the signal causing errors.
I've been looking at systems where increasing from 0.5m to 1m cables creates a significant (>1%) increase in latency for network traffic so it's not always about signal integrity.
Signal degradation is rough. I had the most messed up problem with a long usb cable extender, and it wasn't a matter of "it either works or it doesn't". The USB cable was "mostly" working but my mouse would occasionally freeze for a second and then resume. Mostly harmless, but for a gamer this won't work. Also the lights weren't syncing on my peripheral devices.
It was hours and hours of troubleshooting before I figured out it was the usb cable extender. I didn't understand about signal degradation in long cords. It's really, really frustrating.
Size matters [first obvious joke]
this comment has 69 likes lol
+Obelisk Extender It's not size, it's circumference, how well isolated it is.
AKA Girth.
Thanks Linus! In the market for purchasing HDMI cables at 30' or 40' long and needed to know if a repeater is necessary. I thought 25' was the safe limit for HDMI... although same are saying that is true depending on the build quality, at which point is a matter of how or miss, or x out y cables are likely to have issues at the given length.
Darn, I wanted an external GPU that was 200 feet away from my gaming rig. Thanks for ruining my dreams.
The only UA-camr who make serious diverse differences..most of the rest do just phone comparisons but this guy's goes beyond to computers and their peripherals ...u the man keep it up
Can you explain why Ethernet cables are so much more efficient at transferring data over long distances? Could you also talk about this problem in relation to internet/cable service? :)
i love the little bloopers the editors leave in. The bit with the cell phone was funny. Makes the entire video feel more "real"
I guess this answers why I can't find a 10 foot USB 3.1 Gen 2 type c connector cable.
How long hdmi 1.4 cable will be workable ? I want to keep a good 10feet distance from my 60 inch full hd t.v. while using my cheap 12inch laptop asus eebook 12. Please answer if u know or have any idea.
Yay! A clear, concise and comprehensive explanation of the advantages, and limitations, of extending data cables. Thank you.
considering what Linus said about the maximum lengths for those cables, I'm pretty happy the only long cable I need is for ethernet, everything else being under 1m long
5:25 wow got one grip on that dog
There are a number of technical errors in this video. First, 1:29 you mean resistance or attenuation, not impedance. The characteristic impedance of a cable doesn't change with distance, but signal attenuation does. This is due to dielectric loss as well as ordinary resistance; worse, dielectric loss increases at higher frequencies, which is why higher bandwidth signals (eg USB 3 vs USB 2) are more sensitive to length than lower bandwidth signals.
3:30 it's not reflections that cause the problem, it's dielectric loss, and reflections are caused by impedance mismatches (usually due to crappy cable and/or connectors). Delay has nothing to do with it, except insofar as delay affects how reflections degrade a signal. A properly designed impedance-controlled transmission line (which these sorts of cables are) should have minimal reflections, can have wide bandwidth and can be much longer than the highest frequency component it carries.
Example: the actual cable of CATV has a bandwidth of around 800 MHz or so and can carry multiple gigabit digital signals in DOCSIS 3, yet CATV cable runs are commonly way longer than anything you'd find in a single household (and can be miles and miles with appropriate regeneration). The difference is in the design of the protocol, the quality of cable and launch power amongst others.
Aside from dielectric loss, there are no analogue-domain limitations in principle on the length of a cable, provided it is properly impedance matched. (Example: SATA and SAS are the same protocols and use the same sort of cabling, but SAS has a higher voltage drive so it can reach further.) There's one exception to that: some protocols are designed in such a way that excess latency (delay or response to a message) can break them. GSM phones, for example, have an absolute limit of 35km, regardless of signal strength or boosters.
3:40 Reflections don't cause damage except in high power RF transmitters because there's just not enough energy in them to do any damage. They will, however, degrade signal integrity which will make the signal unusable.
Linus says impedance, not characteristic impedance, so he's right in that regard.
Dielectric loss causes the signal to not reach the other end, but we're talking about a tighter limit when the signal reaches the other end intact-the device needs to ACK back fast enough. USB is half-duplex but apparently requires a short ACK time. Impedance matching solves the amplitude of reflection so that the host can send another bit faster because it does not have to wait for the reflection to settle nearly as long, but the ACK requirement still limits the delay. Linus is half-right in that reflection can matter, but he fails to point out another limit when reflection is limited via matching circuits.
You're right that "the difference is in the design of the protocol, the quality of cable and launch power amongst others". Depending on the combination of these factors a standard may hit one limit before another.
The USB committee thinks that reflection can damage the circuit though www.usb.org/developers/usbfaq/#cab1
> Linus says impedance, not characteristic impedance, so he's right in that regard.
Not really. Impedance and attenuation are not the same things. Attenuation is a combination of frequency-dependent dielectric parallel loss and resistive (ie non-reactive) series loss, both resulting in heat dissipation in the cable. Resistive loss gets worse with frequency because of the skin effect, but that's different again from dielectric absorption.
As you say, dielectric loss causes the signal not to reach the other end of the cable because it's all gone as heat, and there's nothing you can do about that except get lower loss cable or amplify the source driver.
Impedance (characteristic or lumped), OTOH, is about power transfer. You can transfer all developed power at any impedance (within reason) provided source and sink are matched with the effective impedance of the transmission line.
I'm simplifying a bit: you can't easily compensate for impedance mismatches in a transmission line with a matching network, however you can use RF traps or stubs as notch filters to filter out specific frequencies, but that doesn't work with baseband signals.
> Impedance matching solves the amplitude of reflection so that the host can send another bit faster because it does not have to wait for the reflection to settle nearly as long
As you say, impedance mismatches result in reflections that reduce the power delivered to the load - but the energy hasn't gone away as with attenuation, it's merely not going where it should. Reflections also degrade signal integrity as well as reducing power available at the load.
In a properly impedance-matched, load-terminated system, you don't need to wait for anything to settle because all transmitted power is fully absorbed by the receiver's terminator and there is no particular limit, save for attenuation, on the rate at which you can transmit bits down a properly matched transmission line.
Source-terminated systems achieve the same ends but depend on constructive interference from reflected wavefronts to build up full signal magnitude (c.f. parallel PCI reflected-wave switching).
It's been too long a go since I studied source termination since none of the designs I've worked on use it and I can't remember what happens when the bit rate approaches the return-reflection period or what the implications for USB SI (as opposed to ACK times) would be.
> when the signal reaches the other end intact-the device needs to ACK back fast enough. USB is half-duplex but apparently requires a short ACK time.
True, but this is a protocol matter, not a property of the cable and the time scales are completely different.
Even at a pessimistic 50% c, signals still go about 6 inches per nanosecond or 20 ns per 10' cable. From memory, the polling period of USB 2 high-speed is 125 µs which is about 6000 times slower than the propagation delay in a 10' cable and 600 times slower than a 100' cable (if you could build a lossless cable), which is still plenty of time to return the ACK.
The cables FAQ you linked talks about a budget of 26ns cable delay for the sake of signal integrity in badly terminated transmission lines, not because of ACK timeouts.
I'm not sure what the exact timeout is on USB. One source I read suggested 50 ms, but that might only be for lower speed USB devices, and that's 6 orders of magnitude slower than propagation delay.
> Linus is half-right in that reflection can matter
Yes, but for the wrong reasons, hence my OP.
> The USB committee thinks that reflection can damage the circuit though
They're suggesting that, under the right circumstances, there can be enough constructive reflection interference as to damage the driver.
Assuming adequate ESD protection, that seems unlikely because I don't see constructive interference amounting to kilovolts.
Besides, if I remember how source termination works correctly, the outbound wavefront is 50% magnitude and the reflection builds up to 100% magnitude. If USB is source terminated and setting aside inductive effects, it shouldn't be possible to get > Voh.
Thanks for the reply. I'm in computer engineering and this conversation again proves how little do I know outside of my own comfort zone. One more question though: why does the USB committee have a tighter limit on low-speed cables (18ns) than high-speed cables (26ns)? This doesn't quite make sense to me and I thought the only reason is the speed the device replies, but as you said it shouldn't matter here. Do they assume low-speed cables are crappier?
> I'm in computer engineering
Nominally, I'm a computer scientist but I've ended up doing mostly electronic engineering in my professional career, plus I have a recently-acquired interest in software-defined radio. Just one of those things, I guess.
> One more question though: why does the USB committee have a tighter limit on low-speed cables (18ns) than high-speed cables (26ns)?
Good question. I'd have to closely examine the USB standard to answer that properly, but I don't have a copy of it to hand.
I'm not used to allowing for ringing and poor SI; I'm much more accustomed to ensuring that there is good SI and as little ringing and ground-bounce as possible. IOW, design the protocol to avoid bad conditions, that way you don't have to compensate for them.
USB is a truly awful protocol (I built a USB HID for a flight simulator), but it's cheap and we're stuck with it.
> This doesn't quite make sense to me
Nor to me.
Normally, propagation delay is a sufficiently small proportion of processing latency that it is largely negligible. For example, 25 ns is 2.5 cycles of a 100 MHz clock, and even that is fairly slow by modern standards. You can do bugger all in 2 cycles, which illustrates why processing delay dominates propagation delay.
> Do they assume low-speed cables are crappier?
That would be a reasonable assumption ;) I am sure that cheap, low-speed devices have terrible electrical/SI characteristics.
USB is a cheap protocol designed for low cost devices. So is PCI Express, albeit on a slightly faster and smaller scale. Were it otherwise, it wouldn't gain sufficient market up-take.
No offence even though it's ages ago ... No one likes know it all's and the words used depend on your country
One thing that should be mentioned when talking about electrical cables and wires. When you use cables and wires that are longer then you need and you create a tangled mess you are probability creating impedance along with your mess. Of course if you are one of those people who take care of the mess problem by coiling your excess wire or cable are of course building impedance coils. This can happen even with shielded cables depending on how much electromagnetic bleed out your cables have. Speaker and power wires are especially susceptible to this. I know that I'm stating the obvious but a lot of people seem not to think of this considering some of the power and speaker runs that I've seen.
The theory is nice. Now take that subject to LinusTechTips and let's see if an HDMI cable will start to fail when surpassing 15 meters.
that face of that woman at "longer doesn't necessarily mean better" is just priceless! Nice going finding that on that service you guys used to put out there all the time lol!
Stylosa once told me that cable length doesn't matter... ;)
"Cable length, does in fact, not matter" ▬ Stylosa
TheOneCut I love him :D
I swear this man and his team post the most useful videos
"longer doesn't necessarily mean better"
no wonder linus is single..
Rico he isnt tho
lol
To be fair, it's not like holding a particular opinion changes one's... "cable-length".
Rico single with three kids and a wife
Rico Single? The dude has 3 kids and a wife...
I'm sure no one else can match my brilliance when I make a fantastic quip that has never been heard before.
"Size isn't important. It's the motion of the waves."
No, Linus, I'm not building a website. Thanks for asking though.
Great video. I do fiber optic splicing and fusing occasionally at my job and it is very tedious work. The machine test for DB loss in the fuse. The worst I accept is a .02 DB loss.
3:50
So everyone has to insert their cables into one hub? Hmmm......interesting!
It's a combination of length and thickness. You also need to practice your technique. You can't just ram it in. Make sure it's aligned correctly or you could damage the socket
"Does length matter?" you wanna find out linus? 😉
he already knows... he just told you in video.....
I have a projector setup with 10 meter power cable and 10 meter HDMI running in a cable channel on ceiling & wall...Works well.
2:19 quote from ricegum
0:37 If you wire cables in this manner, you shouldn't even be allowed to touch tech.
But can it run Crysis?
A big thank you for the simplicity of explanation of such matters. This particular video was a big help with a recent upgrade I am working on, thanks again.
why do the little clips on the ends of Ethernet cables always break?
Probably because they are really weak and fragile plastic with a weak joint.
Working with building fiber optic networks and i can safely say that you can get cables up to 6 kilometers without any delay nor data loss (easily longer also, issue is that you usually cant buy longer cables then that without putting a weld somewhere)
The onlything u really need to care about is to not bend it to tight since it will make you loose signal strength.
The reason you cant have long length on some cables is due to the fact they use cheap materials or simply have to big cores. nowdays you use SM (Single mode) instead of MM (multimode) which have increase the lengths dramatically. This is the main reason we can now get fiber to home not just companies. The smaller the core the less signal loss
0:57 I thought he would talk about the sponsor lol
Note: Since you are using specs in the first place: 100m solid core (as a replacement for the permanent/horizontal cable?) is out of specs, it might work or it won't or something in between for people who like troubleshooting. For regular patch cables (AWG24, stranded) the max length would be 85m.
3:27 silence phone like a pro
Scratching his nuts like a pro, i didn't even notice
These educational videos of yours are my favorite, I love learning about technology like this, when I think of you, these are the videos I think of. I didn’t even know these weren’t on your main channel! Haha
Does size matter?
i think also if your cable is long enough to have enough resistance to cause a voltage drop to the point where a logic high is no longer reached, then there go your ones and zeros because all youll get are zeros
My gf dumped me because my length wasn't at least 20ft. 20ft!! WHO NEEDS ALL OF THAT? I can hook up my HDMI from the cable box to the tv... what more does she need?
😑
Honesty?
Well, having a really long cable also affects the signal speed a lot, which can potentially give noticeable delays. The signal in an optical fiber travels at the speed of light in vacuum divided by the refractive index, usually about 1.5 for glass, meaning that it's ~33 % slower than in vacuum. For electrical cables, both digital and analog, the signal speed is probably less. For the cabling used at home, this probably doesn't matter much, but it IS measurable and scales with cable length.
"Length can still matter" 😅 ya see, i'm small but super effective
this video is still so relevant today.
Yesterday, my friend asked me the does HDMI 2.1 cable length matters... I request the length since in most cases it does not matter for in-home us. But he said he saw some "post" said matel cable can not be longer than 5 meters... At the moment I am so confused that does "non-metal" HDMI is a thing....
I love you linus
This channel answers all the basic questions that keep popping up in my mind ❤️.Love from Bangladesh 🇧🇩
জয় বাংলা
5:14. is that... is that a 1000 bucks cable? oh god apple is starting to go too far on this one...
I have come across this comment after the Apple $1000 monitor stand. Nothing is too far for Apple
They had no idea...
i also… recently bought a fibre optic, HDMI cable; and they are really good too. Especially for very long lengths. I’m using this fibre optic cable… from my pioneer receiver, into the tv.
Friday 3rd February 2023. U.K. Southampton
length and girth matters ;)
it was funny the first 1000 times it was commented
Linus, the light in a fiber optic cable does not diminish as a regular point source of light would. Attenuation in a fiber optic cable happens by a completely different property and has more to do with the refractive indices of the fiber and the cladding around it.
34 view 78 likes...
totally viable... youtube logic
PC Master Race I think a view only counts if you watch more than a % of the video, while a like is a click based count, if I like the video as soon as I start watching it, the like counts, the view doesn't (yet)
+Xero no if you click on the video it's a view.
Donald it doesn't work that way. It only registers one after 15s of any video to prevent the viability of clickbots. They used to be a big problem until the limit was added before adding a view count.
It register after a few seconds....
Back when UA-cam launched it was click based. But now it's duration based. I was just making a joke guys, not make it serious..... Have a great day
also depend on what your using the cable for...
if your using it for DATA transfer then it can matter, but generally the shorter the better
as for things like USB charging, of say phones, speakers etc the length on the cable is less of an issue.
I did find a shorter USB seemed to charge a tablet faster. It would make a good experiment.
It matters, especially when ladies are around :P
Tbh it's one of the first things I think about ahah. I'm extremely/analy clean and organised. Cable organisation and the cleanliness of the set up is very important
Remember: it's not about the size; it's what you do with it.
You should note that resolution matters for HDMI. My installation guys connected a 50ft HDMI cable from my 4K player to the projector, and I noticed some black fuzzies on the screen that I thought were from the encoder or something and came with the territory on 4k. When we got a different 4K player those fuzzies got even worse... That's when I researched that 4K is supposed to use shorter cable runs so I put in a 25ft cable and everything was crystal clear.
On USB (and firewire) things like a keyboard you won't notice a difference as you approach the maximum cable length. However, when I had maximum length cables for the medium (3m like you said) there were brief gaps in communication between my interfaces and Pro Tools that result in the recording being stopped. I changed to a shorter cable length and this problem went away.
Also, some optical formats like MADI are getting up to thousands of meters in length. Those cables are getting up to thousands of dollars in cost too though.
"but that dose not mean length is irrelevant"
-Linus 2k17
*does
I thought it was a james veich reference
the only time you get cross talk, is when you run your low voltage to close to your line voltage. as for fiber optic they can run fiber cable under ground for quite a few miles depending on the diameter of the cable, but if your more concerned about voltage drop. then use a thicker wire
What kind of Tech guy is he when he's using an Iphone.
Our whole IT tech department is using iphones, because "it just works"...
@@awdadwadwad1723 jojo reference
Everything he said deserved a like.. but the last quote deserved a stand up 👏 well played
at some point I start counting Linus inhaled
Резо Георгадзе what?
KOTYAR0 what?
A lot of factors matter in the design of a cable... Length and gauge(diameter of cable) will affect the total resistance of the cable. Note also the material but most use copper. The relation between the total resistance of the cable and the voltage will affect the amount of current in the cable wich will determine the intensity of the magnetic field around the cable, wich can act as an inductor wich can filter out some signals and cause noise and interferance. While designing a cable, we have to take in consideration the material and the gauge of the cable and also set limits in length depending on how the signal works and the voltage at witch it is sent, ect...
Do you love me Linus
1:27 you actually want impedance to be matched in many cases; the word that should go there is "resistance". Also of note, many cheap cables will increase the outer jacket size, but still use a crappy (or even crappier!) gauge wire, which doesn't do you any good, even if the cable is thicker.
Me, watching this video through my 2019 BenQ GW2280E with Vga...
Am I a joke to you?
The nature of digital is that the information could be transmitted perfectly. Error correction could catch any bit flips. Although the error rate of a cable transmission is negligible.
But if the error rate becomes too much, you have to resort to dropping the bit rate. The reason your Skype is noisy is NOT because digital isn't perfect but because it's real time so it has to make do with the errors to remain real time
So did the Russian government accept your offer? I want to know what you said in that phone call dammit!
TL;DW
Analog Cables: Shorter and thicker cables are better.
Digital Cables:-
HDMI: 15 metres
USB:-
2.0: 5 metres
3.0: 3 metres
3.2 Gen 2: 1 metre
(Can be extended with an active cable or a repeater)
Ethernet cables: 100 metres
Optical cables:-
Toslink: 10 metres
Thunderbolt 2: 60 metres
Thunderbolt 3:-
No active cable: 0.5 metres
Active cable: 1-2 metres
When she says “Go deeper” but you’re as deep as you can go or “That’s too much” and you’ve only gone about 1/8 to 1/4 of the way in.
men, dont be too self conscious about your length, we're all different in this world and thats what makes us all so unique.