Dr Strangeport: How I learned to stop worrying and love the Displayport KVMs
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- Опубліковано 5 вер 2024
- Wendell is back at the white board, this time to talk about Displayports!
Texas Instruments PDF: www.ti.com/too...
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Intro and Outro Music: "Earth Bound" by Slynk
Other Music: "Lively" & "FollowHer" Zeeky Beats
Wendell's Mom: no Wendell I'm not going to get you a $15k cable tester for Christmas
Wendell: but all the other boys have got one, Steve even got a fan tester. So unfair!
Yeah didn't Linus get a cable tester like 3 months ago?
"This was a quick look" -Wendell
I hope one day we get the LONG version.
Your KVM switch saved my work-from-home life as old ConnectPro KVM almost drove me to insanity. Thank you for the brilliant work, Wendell.
Can I ask what model you had and why you didn't like it? And how Level1 improved? I'm thinking of getting the display port 1.4 kvm they had.
ConnectPro is trash. spent > $500 for a KVM switch for dual 4K monitors (120hz) and it does NOT work. The USB stuff also kept disconnecting.
There's a reason why I bought all of my cables from you when I bought my dual monitor four computer KVM from you. That reason is that I didn't want to have cable issues 🙂
This was super interesting!
A year ago I got a Surface Pro 7 with a usb-c port and DP1.4+dsc support, but after none of the hubs worked for 4K 60Hz I started digging. As it turns out intel had problems with the dsc implementation, and even removed the DP version from ark. It was annoying, and made me question a lot of reviews of the docks and hubs.
God, whoever is pairing stock cables that don't work with their own monitors should be shot into space.
Second to that!
That sounds like a life-hack for a cheap trip to space.
...or flushed into a volcano along with the cables.
@@tommix6733 I'm in agreement with your proposal.
I was playing Zelda Breath of the Wild on my Nintendo Switch connected to my Dell U2717D via HDMI and encountered a screen blacking out issue in a specific scene. In the early sections of the game, there's a rock monster mini boss battle in one of the Hyrule forest areas. When you deliver a hit, the screen would flash white, which sometimes caused the display to black out/reset. As the Nintendo supplied cable was still connected to my TV, I thought nothing about using the existing HDMI cable plugged into the Dell monitor. Since then I've learnt about cable quality, and that not all HDMI 2.0 / 2.1 cables are as they claim to be. (Bear in mind the Nintendo cable is not even rated at HDMI 2.0, but the quality is much better and has no issues).
I love how nerdy Wendel is ... $15k cable tester :P
Possibly because Linus bought one for testing HDMI cables.
@@SirHackaL0t. Possibly because Wendel develops display port KVM, and this equipment is for that development
Did he buy the one that Linus bought after Linus made his video?
@@MrV1NC3N7V3G4 Linus bought one for HDMI
@@MrV1NC3N7V3G4 The test screens look identical.
This is the first time someone adequately explained to me why some cables are better than others and why even "audiophile" digital cables can have merit.
Thank you Wendell and Level1Techs for this!
Better quality cables *can* have merit, but it should also be noted: that doesn't mean most of them do, especially "audiophile" and similarly marketed stuff.
And with digital signals it's usually more obvious when they misbehave, it isn't a case where clarity increases with the quality of the cable. There are broken cables, flaky cables (that work in some conditions but not others), and good cables, that work in all specified modes, basically.
Looks like its time to make some Data cables out of Some speaker cables and see how well they hold up to the claims!
I dream of a future, where all hardware manufacturers have this level of passion, to make products that do not suck.
Alas, greed would never allow it, but I can dream, dammit!
Great piece of content, please do usbC alt modes and hubs next!
I had to watch that twice before I felt I was really following. There was a lot of info packed into that video. Certainly does explain a few issues I've encountered with display adapters
With all the similarity between all these different devices, it's a little surprising we don't have some unified design yet with the only real differences are the run lengths and maybe connector to prevent compatibility issues.
Like you said, if everything is reinventing PCIe, it'd be really cool if they just switched to using different versions of PCIe.
Then instead of trying to take a Displayport cable and find a way to run USB on it, we'd just change from a PCIe3x1 cable to a PCIe3x2 cable for example.
Though there are almost certainly issues with that method that I'm unaware of, it just would be cool to get all this shit on the same page.
Wonderful video. That thing with a DP cable working with one GPU and not with another, I tried that and mystery explained finally!
Would love to see a video detailing how Thunderbolt 4 works in combination with a discrete GPU with the Alder Lake platform when the motherboard has no DP IN port at all. I can't seem to find any information on this how it works, if it works at all?
Agreed! Very nice to see some actual information about what can be going on under the hood on some of those classic "This cable just hates this video card/monitor/usb port" type situations.
Any news regarding active DisplayPort 1.4-to-HDMI 2.1 adapters that actually work? Don’t even care about VRR anymore, just looking for 4K/UHD 120 Hz/Full-Range RGB so no chroma subsampling.
Edit: Don’t post a comment before completely watching a video 🙃
Hehe 😋
Thanks for the in-depth analysis Wendell!
26:35
"Ahh, yes! Ze terroir of zees chip will compliment perfectly ze frequency response character of my cable!"
*Chef's kiss*
Best thumbnail in the history of thumbnails. Instant thumbs-up
Thank you Wendell. Can you make an in-depth video about the abysmal state of dongles and why most of them are so bad (including multi-hundred dollars ones)?
So glad to see someone elses office is just as messy as mine!
Well that was... the bomb! XD
Can't wait to see that front panel testing.
One of the better commercials I have watched lately :)
Really cool video.. Seen the graphs what the wires are, but this video really explained everything really well, and went even further .. good job!
10/10 recommend thick tip pens so in the future if you ever do these again we can see these a little better at a lower resolution (a mobile data user). On a side note the display port cable that came with my monitor even has blackout issues at 1080P 165 Hz. I wonder if it's a decent cable or not
The rack mount fan noise in the background couldn't be more Wendell.
8:25
RX Vega 64 has poor display port link training?
I see.
I suspected my issue with my Valve Index was a link training issue, because I can unplug the display port cable and plug it back in or power off the headset and turn it back on until the link works and then it works fine for the entire session.
It is interesting to know that there is a potential physical layer tx parameter adjustment for this that is exposed in the driver rather than needing to fumble around behind my computer with my headset on half the times that I start VR.
(The issue also did not happen with my original HMD, only with the warranty replacement one I got after I broke the first one)
I am just a lowly simpleton, but this video has motivated me to learn the science of the things you speak of...thank the gods my good man!!!
14:01 DSC is not lossless. It is marketed as "visually lossless", meaning that it is actually lossy but the losses are not (supposed to be) noticeable by the human eye.
DSC also adds much less than one frame of latency. So less than 8.3333 ms if you're at 120Hz.
@@bengrant7654 he never said it added a frame, he just compared the amount of latency it adds to the amount of time it takes the display to refresh, the explanation was kinda unclear
I just started down the DisplayPort KVM rabbit hole yesterday. Perfect timing.
Man, can't wait until the USB-C with power delivery KVMs are released!!! Save us Wendell!
I'm so glad you took the effort to do this stuff. I just bought one of your KVMs because my expensive amazon one started crapping out after a year of use and never handled 120hz 5120x1440 correctly.
You should have mentioned what common mode noise is when you talked about the ferrites.
Yeah there's a couple rabbit holes I probably should have pointed out at least
@@Level1Techs Yeah :-) I know there's only so much you can fit into one video. But that's crucial to understand why the bead doesn't or hardly interferes with the high frequency data signals in Displayport, because they all use differential signaling with two wires each (including the AUX channel).
Thx Wendel - hope to get one of your KVMs. Was hoping to hear more about the actual KVM, but still interesting about the cables.
Is it still March?
That thumbnail is gold.
I enjoyed this, understood some of it and other parts went over my head.
Displayport 2.0 will fix everything and all devices will work perfectly forever and you won't have a ton of new problems on top of the 1.2 & 1.4 headaches..
Thanks. Good explanation. Display port is a complicated protocol.
Could you do a brake down explanation for HDMI?
I'd also like an explanation on hdmi, I always felt it is more reliable than DP
@@jorelplay8738 HDMI has a lot of signal negotiating due to the copyright protection and HDMI licensing on the chipset (I believe this is why. A good 1h long video would be ace)
Also I bit on the pros and cons of the two systems.
thanks Wendell
Awesome, explanation.
Thanks professor
I would love to hear a drunk Wendell rant on display port cables now!
So the cable being broken is way more complicated than you think... But the solution is the same when having problems with video peripherals: 1st step of troubleshooting after narrowing it down to just the screen, replace the cable with a known working cable (with this video making me amend it with "... In the same configuration as the problem system.")
Awesome video, Wendell. Sending it off to all my techie kids, making sure they watch it...
The video I didn't know I needed, and that I was interested in! 😅
thank you for all that you do wendell!
I love it when Wendell goes full Wendell !
eDP was designed as a replacement for lvds displays in laptops...
Which is where it mainly gets used afaik.
Using it for external displays was never the intent afaik.
I mean that's why it is called an embedded display port eDP.
The title alone is worth at thumbs up! :-)
That was very informative. I recently got an RTX 3080 and I've been having issues with random noise and screen blanking. I tried all the software stuff on the forums but nothing helped. I just swapped out the cable with one I had on hand and so far no issues, but I also ordered (what I hope is) a higher quality one.
hearing what all could go wrong between the graphics card and the monitor,
really reminded me off the interview with Greg Kroah-Hartman, it's a freaking miracle stuff works lol
Good job!
pre-emphasis indeed; best buy has been solid as far as what OSD tells me on 1.4DP; mines monitors are the ones what with gsync qualifications (stickers) so they might be lieung like a cheap rug maybe?
Ahh, A white board presentation. I miss those :(.
25:57 Regarding Apple and hotplug: I think pedantry only describes situations where the pedant is correct, but doesn't apply to those who are wrong. Apple seems to be using the protocol incorrectly if I understand correctly, so that's not pedantry. (This comment is more like it, unless I'm wrong somewhere.)
Unrelated Q: Can I drive a 4K120 TV with HDMI inputs only with your KVM switch, switching between a desktop PC (has DP and HDMI) and a laptop with Thunderbolt or USB-C + DP? VRR would be an optional nice to have.
Another interesting video, some of the best cables I have are the cheapest ones you could buy.
I was able to use to the infomation in this to help make a screen that I use work better when power it on or if. Turns out garabge or damage cable. The cable it using is at least 4 years old. Running a 2k 60 hz screen
Can't wait for optical cables to be the standard for DP and other high bandwidth standards/cables
I sometimes forget Wendell at some point was taught the wealth of knowledge he possesses, otherwise I naturally assume it was simply imbued upon him at birth
It came as an builtin OS feature, his soul is full of learning and wisdom potential!
Oh god I hope you/someone is working on that 'lunacy' lol it sounds super useful
You do so well at disseminating information. I think its time to make the video. Explaining how Americans have paid for nationwide fiber!
Because I honestly don't know the when, how, or why. But would really like to have you explain it to us!
Any time he goes to the whiteboard I'm excited.
I just gave up and went for optical displayport cables, which solved all the weird issues I was getting
Nice Tech Talk Wendell. I have been using synergy for allowing me to move between my 3 computers. Last time I used a kvm was a decade ago. Maybe I should consider looking at one of your offerings some day.
Great information :)
fantastic video!
Makes sense now why my cable matters adapter/dock thing can do 4k@60 over usb-C with usb2.0 for peripherals. They must use that AUX channel for the usb2.0 data. Every other usb3.0 enabled adapter only supported lower resolutions and usb 3.0.
Have you ever thought about finding a display port manufacturer which you can contract with to make level 1 techs dp cables? That way you have a reliable source of dp cables!
store.level1techs.com/products/display-port-14-cables-120-cm-amp-200-cm
More, more, more! I love this content.
Hi Wendel, could you also educate us about HDMI? Specifically how does USB C to HDMI adaptors work. And if you know a good adaptor please let me know. Thanks.
ah you got the tester! good job.
I'm really jealous of this mans IQ
eDP is in use in pretty much most PC laptops as far as I know. I mean that's where you'd expect a slim screen and brightness and color controls from software/OS/GPU.
I think smartphones as well. Though it's been a few years since I remember reading about it. Basically most places where there's an integrated screen and power is a concern.
Most pc laptops use lvds not eDP.
@@Knirin Well eDP is the replacement for LVDS so I think in the higher end devices that need higher bitrates need to use eDP
The 20th pin has caused me so much problems. Even when I was using 1080 60hz displays a few years ago, I had display port cable issues.
Dear God Wendell the red on red is just a floating head and arms
Very good video, thank you
THIS is why i patreon
Whew! Thank fuck I get by with just using HDMI on my PC/monitor and PS3/TV. ;-) But as usual, I still watched the whole video because I never want to stop learning, and there is always a small chance that I may be able to help someone in the future who uses displayport.
Amazin video Level1 Team!
Thanks for this, good brain food 😋
speaking of fun DisplayPort stuff. If I connect my monitor to my computer (via a amd polaris card) the post code display on the motherboard somehow lights up even if my computer is not connected to power, as long as my monitor has power. wonder if the 5v's are interconnected over a 20th pin ;)
This is the video I never knew I needed
Still rather have 10b or 12b color 1080p, than 8b 4k, as an end consumer. I can see lossless [10b or 12b]4k being useful for professional video capture and editing.
When i get up from my desk chair, the spring in the chair makes this pop. It causes my screens on my desk to flicker of and on again that are connected via displayport to my laptop.
I had a DisplayPort cable that would not work when the card was in a vertical Mount. Took weeks to figure it was the cable and. It the pcie. Extension
My Polaris also has a shady DP connection as I only have a good signal only if I downclock + downpower the card by 5-9%. They cheaped out on it and it took me years of troubleshooting to find the exact way to eliminate the short black screens. The emphasis change at driver level did not made any impact.
TEST ALL THE CABLES!!
Take my updoot to help pay for that cable tester!
Over the years I have had a lot of issues with hdmi and dvi displays on nvidia cards. I am sure that has a rabbit hole of its own.
What about a USB-C or Thunderbolt dock + dual head KVM for displayport. I mean for one USB-C laptop and one Displayport Desktop
I wish thunderbolt was just.. everywhere, I'd love to use it, but I can't count on say, multiple thunderbolt outputs from a graphics card, so displayport and HDMI it is.
Hoping for a video explaining HDMI 2.1....now that is has been USB'd.
So then what's the point of the power pin, if it must not be connected? If it's useless, it could be dropped and we would have a (slightly) smaller connector. What am I missing?
No I am quite sure I do want to control my monitor from the os. I installed twinkle tray
I really like this video I learnt something pretty cool
DisplayPort? Never heard of her. Ivy Bridge i7 IGA, twice re-capped motherboard user here, DP would be nice but I have nowhere to plug it in. Thanks global situation, very cool!
DP is annoying on Windows if you have more than 1 display attached. When it wakes up all your windows will have moved to one screen regardless of where they were before the screens went to sleep.
I wanted to check things before I commented, but as a multi display via display port user on windows I only have that happen if I physically power off one of the displays. Sleep does not do that on my system. My GPU only has display port connections so in my case not much say in the matter but I don't have that happen from sleep only turning a monitor off.
Wendell....you should build yourself a lightboard...and be really pro? Great video...thanks learned some stuff of DP and why my monitor sometimes switches of/on....cable seems to be the issue then...
I gave up trying to use DP for my Gigabyte M32U, it would just randomly black screen using it every 10-20 minutes. The HDMI seems to work fine, I'm not sure whether it is the cables, the monitor, or the GPU.
Can we get some videos of Amazon cables being tested, finally!