Dr Strangeport: How I learned to stop worrying and love the Displayport KVMs
ฝัง
- เผยแพร่เมื่อ 27 ก.ย. 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?
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.
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.
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.
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).
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!
Great piece of content, please do usbC alt modes and hubs next!
Best thumbnail in the history of thumbnails. Instant thumbs-up
Thanks for the in-depth analysis Wendell!
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
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 😋
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.
Man, can't wait until the USB-C with power delivery KVMs are released!!! Save us Wendell!
Really cool video.. Seen the graphs what the wires are, but this video really explained everything really well, and went even further .. good job!
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.
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!!!
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 🙂
I just started down the DisplayPort KVM rabbit hole yesterday. Perfect timing.
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
Is it still March?
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.
Thx Wendel - hope to get one of your KVMs. Was hoping to hear more about the actual KVM, but still interesting about the cables.
I would love to hear a drunk Wendell rant on display port cables now!
I enjoyed this, understood some of it and other parts went over my head.
thanks Wendell
The title alone is worth at thumbs up! :-)
I love it when Wendell goes full Wendell !
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).
Thanks professor
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
Oh god I hope you/someone is working on that 'lunacy' lol it sounds super useful
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.
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!
More, more, more! I love this content.
fantastic video!
Great information :)
I just gave up and went for optical displayport cables, which solved all the weird issues I was getting
I'm really jealous of this mans IQ
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.
Any time he goes to the whiteboard I'm excited.
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.")
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
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.
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.
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.
Amazin video Level1 Team!
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?
ah you got the tester! good job.
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.
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.
Very good video, thank you
Thanks for this, good brain food 😋
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!
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.
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
THIS is why i patreon
TEST ALL THE CABLES!!
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
What about a USB-C or Thunderbolt dock + dual head KVM for displayport. I mean for one USB-C laptop and one Displayport Desktop
the memes are strong with this one:) love this show
So, when can I buy Level1 certified cables?
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.
Why no Optic Fiber monitor cables?
So when is the kvm dp 1.4 stuff going back in stock?
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.
I really like this video I learnt something pretty cool
How does USB4 change this situation?
_______engagement_______
Edit: cable tester is sweet though
Does anyone know of a device where you can connect 2 laptops, via thunderbolt to it and it has 1 thunderbolt out which you can connect to a dock? I have a thunderbolt dock that connects everything to my personal laptop but then I have a work laptop. And currently I have to keep unplugging the dock and moving the cable to the other device and plugging it in. Be nice if I could just hit a button and it switch between them. But I can't seem to find anyone that makes such a device
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.
My first thought in watching this was "Do you have recommended cable brand?" and after watching I realize it may not be so easy to answer. But, do you have a recommended cable brand for display port?
He mentioned Club3d cables in a previous video as ones he has had almost 0 issues with.
I thought you meant KVM as in KVM. Never knew these switches are called KVM too.
i learned alot, but cant use it... i am still waiting for displayport 2.0.
One question: when will servers get rid of VGA + USB A combo and replace it with single USB C carrying both KVM and usb storage? This way server vendors could save a couple of square inches of area on the back of the server and dedicate that to better airflow instead. I understand that ASPEED 2600 already supports DP ?
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.
Oh Oh! those 10,000 USB cables are going to be put to the Audiophile test REALLY SOON! LOL!
Oh Oh!
So what is the best displayport cable I can get on Amazon
He has mentioned in past videos that many on amazon are fake.
For my (yes I know, super old) Radeon HD 6950 I have 4 Displayport and 2 DVI, with 3 DVI monitors: I needed an active DP->DVI adapter, the second adapter is a passive one. Two passive ones won't work, and two active ones make bluescreens.
the active one doesn't have a seperate power supply (so I suppose the power pin is enough)
I understand why active adapters are needed (the card itself doesn't do conversion, probably that's why there can be 4 on a card) but why is a single one enough? the adapter only converts the DP it is connected to.. right?
I guess the only reason 20 pin DP cables are existing, is to put the converter after a certain distance, then go further with HDMI/DVI: perhaps a cheaper method than buying a dedicated active signal booster?
DP and USBC cables are like dating market. Sometimes you connect, sometimes not, sometimes you smash or not, sometimes you date for long time and next day you are dumped.
In theory you should be happily ever after but in reality it is a miserable mess.
You just know that if any cable manufacturer did bother to test all twisted pairs and then label it as 4k60 compliant another one would slap that label on anything almost immediately.
I for one am sticking with standard res monitors till they just reach the logical conclusion of being linked by fiber optic to the graphics output, it works for low latency audio why not low latency graphics?
Is apples shenanigans an oversite or an intentional attempt to push people to only buy apple cables
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.
I wonder how fiber optic cables affect all this.
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!
What is that iPad display port interface? Not finding a video. I'm guessing it's driving an ipad lcd.
I really want a cable tester to my own cables. Then I look at this of the cable tester (which is still cheap for this kind of equipment) and decide that I can probably still order 10 different Displayport cables from Amazon and switch tem around until I have one that work.
Would be interesting to know if there are are probe point in the KVM switches where you could hook up your oscilloscope to see the channel and if that gives any insight.
Me too... I would however also settle for a friend owning one close by :)
The problem with just buying lots of cable (apart from supporting manufactures that produce crap) you don't quite know why a given setup is working or not...
Do you have an HDMI 1x2 splitter (4K120) for next gen consoles?
Soon (tm)
@@Level1Techs Amazing, specially if it has SPDIF.
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...
Wonder if fiberoptic would take on all this problems someday.
Is there such a cable tester for SFF cables that claim to handle 8 GHz PCIe Gen4?
LTT we have this machine and these cables work, these don't... is someone helping you with food.
L1T educating the 101 is like getting you a fishing net and making you self sufficient.
Great video, as a developer I request an in depth explanation of ASSR and e-dp seeding... just kidding I would wish that explanation on nobody.
>Nobody wants to control brightness from you know windows app
I explicitly searched for this. Am I really the only one?
LETS NOT. GOODBYE.
Teach me senpai
👍
I must say that display port and USB-C are a complete mess of specifications. I can't tell any of my friends how this works or if they can connect their new display to their laptop without getting a 'Wendell like' white board
OK, someone needs to set up a service where you can mail cables in to have them checked by one of these machines.
Must get cable tester because Gamers Nexus doesn't have one :p