You need the firmware update from nvidia for 10 siries gpus for sure v
6000 series amd and 3000 series nv about the same.v
My card has the latest BIOS from Gigabyte and I applied the DP1.4 update from nVidia - NVIDIA Graphics Firmware Update Tool for DisplayPort 1.3 and 1.4 Displays
I know Pascal doesn’t support DSC so the most I will get is 120Hz at 4K which is fine for me.
Do you think the 3m length of Club3D cables (CAC-2067 and CAC-2068) will work with the Neo G8, or Fibbr optical cables would be a better option?
The club3d is probably fine. just try to keep the total cable length from gpu to display under 10 feet. since there’s no repeater in the KVm it’s basically “one long cable” and that’s the trouble you can run into.
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Do optical DisplayPort cables count as repeaters, if used on the input side of the KVM switch? I’ve been having intermittent issues with my 4-port dual-monitor KVM (only one monitor in use).
I currently have some 1-meter cables (Club3D CAC-2067) on the input side, and a 10-foot optical cable (Fibbr brand) on the output side. With some source devices, that causes frequent blanking, but it was even worse before I got the optical cable.
I had to add an active repeater between the KVM switch and one source, but that makes the cabling a mess, especially if I have multiple devices that seem to require repeaters.
The offending source device is an HP T640 thin client, but Apple laptops with USB-C to DisplayPort tend to be problematic too. Also problematic are the MiniDP-to-DP adapters that come with various Radeon Pro GPUs.
I’m wondering if using optical cables on the input side would avoid the need for a repeater on each input. If an optical cable acts as a repeater, then I might as well put the money into that rather than into more repeaters.
I can also consider getting a shorter optical cable for the output, but having spare length is nice for routing.
Likely yes should be fine? Most mdp to dp adapters I’ve tested barely pass dp1.2 spec let alone dp1.4.
Moshi usbc to dp is very good with apple and the KVm.
If you have any of the optical cables, I’d be curious to see what the output of those looks like on an eye chart. Is it the same as the input, or better, or worse?
Incidentally, the Cable Matters active repeater seems to have become flaky, and it adds yet more cable clutter. If optical cables on the input act like a repeater, that will be worth the price.
They do act as repeaters, the eye diagram isnt perfect on the fibbr one but give that a try as it generally is a great brand and works well for other customers.
I ordered a 3.3 foot one and a 6.6 foot one, and what they shipped was a 3.3 foot one and a 33-foot one.
I installed the 3.3 foot one between the T640 and the KVM switch and moved the Club3D CAC-2067 cable to the output side of the KVM switch. Yay, no more repeater needed, and the flicker seems to be gone in a short test, though I’ll have to give it a longer test once some wet paint dries in my room.
(Now, to decide what to do with the 33-foot one… Sure, I got a more expensive item for the price of a cheaper one, but where am I going to use a 33-foot cable in a room that’s 10.5 by 16 feet?)
I got the Samsung Neo G8 and the 2m Club3D DP1.4 → KVM → 1m Club3D DP 1.4 will only run 4K60. If i switch to 4K120 the monitor just goes blank. Also if I enable HDR in Windows 11 at 4K60 it flashing, artifacts, etc start happening at random times. I tried with the 1080ti and a new 3080ti and same result so it is not a DP1.4 issue with the Pascal card.
I also tried to get the Mac Mini M1 which has a Club 3D USB-C to DP 1.4 1m → KVM → Club3D DP 1.4 and it won’t show a signal on the Neo G8 either.
I’m thinking I’m going to need to get some Fibbr cables
Yep worth a try for sure. Could be I need to swap the KVm for you but I’d try the fiber cables also.
Sometimes worth trying different physical GPU outputs too. On the FAQ thread one guy had tried 5 club3d cables before it worked.
If you can use dsc that also is usually " easier " on the cabling requirements.
Thanks Wendel. I will give DSC a go with the 3080Ti. I tried on different GPU, different GPU outputs, and different cables.
I have two 1m (3.3ft) Fbbr cables on the way from Amazon using your link in the this thread and hopefully that solves the issue.
If not I will reach out for support. Thanks for your help Wendell. Your support for your KVM is top notch
Oh for 1080ti do you have the optional Nvidia firmware installed? For dp1.4? That’s needed also
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Yes I do have the Pascal DP 1.4 update. Running the update again says the update is already installed. Will have to wait for my Amazon order to come through to see how the Fibbr cables work.
Is it best to have the Fibbr cable between the PC and KVM, or KVM and monitor?
I assume they will draw the required power from the PC or Monitor whichever end they are placed since the KVM is just pass through?
@wendell Any other fiber optic DP 1.4 cables that you know are compatible with the KVM? Fibbr cancelled my order from Amazon US for some rason
@wendell I think my KVM may have an issue.
I used a coupler to daisy chain a 1 metre and 2 metre Club 3D cables where the couple is in place of the KVM and 4K 120Hz worked with HDR enabled. I then turned the monitor to 240Hz and that worked too (Probably because of DSC).
I then tried two 2 metre Club 3D cables with the coupler and that worked too.
I remembered I had a Cable Matters DP 1.4 active repeater (https://www.amazon.com.au/Cable-Matters-DisplayPort-Amplifier-Resolution/dp/B07D949F59/) so I used this between two 2metre Club 3D cables and 4K 120/240Hz with HDR worked. Even GSync worked which I was surprised. I thought this active repeater would break GSync.
I then tried two 1 metre Club 3D cables with the active repeater in between going from the computer to the KVM, and then a single 1 metre Club 3D cable from the KVM to the Neo G8. This time HDR worked at 4K 60Hz, but again attempting to go above 60Hz with or without HDR failed with no signal. If I change the KVM out for the coupler in this config, 4K120/240 works. The only variable here now is the KVM itself.
I’m thinking my KVM cannot drive above 60Hz at 4K. Is there any way to fix this?
You can mail it in and I can run it through the cable tester and/or swap some internal components. There is some snr loss through the kvm that might be a bit worse than a coupler, but generally this should be a fine way to test.
Email me to setup the rma. Its pretty rare, but it does happen.
I’ve emailed Wendell to arrange a RMA. I put through a second order for 2x 1m FIBBR cables from Amazon US and it looked like they shipped this time. I will send the KVM once I’ve had a chance to test the FIBBR cables.
Current tracking shows:
Package arrived at a carrier facility.
Tulsa, OK US
Yay they are on their way.
I also did a bit more testing with results below
3080Ti → 1m Club3D CAC-2067 → KVM → 1m Club3D CAC-2067 → Neo G8:
This still only allows 4K60 where anything higher the Neo G8 shows no signal. I can engage HDR with 10bit RGB showing in the Windows and nVidia panels and it works fine on the desktop and I notice a tiny bit of flickering when playing a HDR video. However attempting to play Tiny Tina’s Wonderlands in HDR results in the screen going black like it is losing signal for a second or so, every 30 seconds or so. I also see flickering on the screen like I did in the HDR video. I found a Reddit post with someone else experiencing the same thing but they don’t specify if it happens with HDR or not (https://www.reddit.com/r/techsupport/comments/uudht1/level1techs_kvm_flickering_only_in_games/). Turning off HDR, the issue goes away.
3080Ti → 1m Club3D CAC-2067 → Cable Matters DisplayPort Repeater → 1m Club3D CAC-2067 → KVM → 1m Club3D CAC-2067 → Neo G8:
Adding a DP repeater and another 1m Club3d CAC-2067 cable between the PC and KVM stabilizes HDR in game. This still only allows 4K60 where anything higher the Neo G8 shows no signal. I can engage HDR with 10bit RGB showing in the Windows and nVidia panels and it works fine on the desktop and in game.
It is interesting that there is a difference in stability of the signal with 10bit RGB HDR enabled between the windows desktop, playing a video, and in game. And how a 3m cable length with a repeater at the 1m mark and KVM at the 2m mark, is more stable than a 2m cable length with only the KVM at the 1m mark.
I hope when the FIBBR cables arrive, I can remove the repeater and have 3080Ti → 1m FIBBR → KVM - 1m FIBBR → Neo G8. The repeater has a side effect in that if I have the KVM set to my M1 Mac Mini and attempt to switch it back to my computer with the 3080Ti, my computer gets real unhappy. Both monitors will not light up and if I RDP into it from another machine, the RDP connection establishes but I get a blank screen. I suspect something controlling the Windows Desktop Environment has crashed, I have a mini dump, but haven’t had a chance to look at it yet. If I can take the repeater out of the equation by using the FIBBR cables, I can switch between the M1 Mac Mini and my computer without issue.
@wendell Thanks for your great support with this. You really stand by your product. I appreciate it. I also understand that my config is an edge case. How many people are trying to drive 4K at 120Hz or 240Hz, and a secondary screen at 4K 60Hz, all through a KVM?
When searching for a KVM that supported 4K > 60Hz, supported VRR even if unofficially, the Level1Techs KVM was the only viable option. There may be some hiccups, but it is awesome the support you provide for these edge case usages like mine that make your product stand out in the market.
I will keep updating this thread, so hopefully in the future if anyone else encounters a similar issue, they will have the solution.
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Success - but short lived - Monitor flickers loses signal after a few minutes
4K120Hz doesn’t work through the KVM still, however 4K240Hz in 8bit SDR actually does. Is this because of DSC is reducing the bandwidth requirements below that of 4K120Hz without DSC?
That would indicate this is a cable length/ signal degradation issue. Still waiting for the FIBBR cables. This was with 3080Ti → 1m Club3D CAC-2067 → Cable Matters DisplayPort Repeater → 1m Club3D CAC-2067 → KVM → 1m Club3D CAC-2067 → Neo G8.
I tried to enable 10bit HDR at 4K240Hz and that was the same as 4K120Hz.
The 1m FIBBR cables arrived and individually they worked fine with the Samsung Neo G8, however unfortunately they did not work with the KVM in the following configuration:
3080Ti → 1m FIBBR Flash144 → KVM → 1m FIBBR Flash144 → Neo G8
4K60 8bit SRGB worked, 4K60 10bit HDR flickered, and anything 4K120/240 failed.
Video below showing flickering in 4K60 10bit HDR and then attempting to switch to 4K120. The Neo G8 is the monitor on the left.
Level1Techs DP 1.4 KVM / FIBBR 1m Cables / Samsung Neo G8
I’ve tried as much as I think I can do from my end.
@wendell I will send my KVM RMA in the next few days and email you the tracking details.
Yep those look right. Tho I just got some 1m fiber cables myself and they’re different than the longer ones. I’ll take a vid once I get yours in and see how it goes. Sorry for the headache sometimes KVm are fun that way. Can’t wait to take a closer look at it.