DisplayPort KVM issue

[zacl]

I have two new computers. One running integrated graphics, intel 770. The other running an RTX 5060ti. I have an IoGear DisplayPort KVM. The 770 machine will work with the KVM, but when I switch to the other input, and switch back, there is no display. I can restore the display by unplugging the cable from the computer and plugging it back in, or turning the monitor off and back on. The 5060 machine doesn’t seem to have this issue. It’s like when the KVM is switched, the 770 machine turns off that port and doesn’t automatically turn it back on when I switch with the KVM. THoughts? It seems like it should be a setting maybe.

[Josh-J-Spiceworks]

@zacl

I can restore the display by unplugging the cable from the computer and plugging it back in, or turning the monitor off and back on

If that’s the case, I’d see if a GPU driver reset would also fix it. Are these machines running Windows? If so, Ctrl+Win+Shift+B should reset the driver and might bring the display back.

If that works, the issue could be resolved at the driver level, but, unfortunately, you’re unlikely to get an official fix from Intel/Nvidia for this specific setup.

My guess is that the KVM keeps supplying the EDID information even when switching devices, but the GPU is detecting that it’s not working (because the other system is now displaying on the physical monitor) and it kills the signal until something changes.

[molan]

I have an RTX 5070 on my personal machine and have similar issues with KVM. In addition to what you describe It also won’t enable the video display on boot via the KVM.

I think the 50xx series is doing some sort of EDID query\check against the monitor to ensure its present before it initializes itself and that the KVMs are not supporting, passing that EDID check properly.

In my case I ended up connecting a additional monitor I had laying around directly to the RTX card, then simply turning off that monitor in windows. Not great, but it seems to make the RTX happy in that it sees and can talk to a real monitor so it initializes itself correctly while allowing me to use my other monitors via the KVM

[jollybgood]

Its a fairly common issue when using DisplayPort KVMs with Intel integrated graphics, especially the Intel UHD 770, Sounds like a DisplayPort link training or hotplug detection issue.

Unlike NVIDIA/AMD cards, many integrated GPUs don’t actively re-initiate signal negotiation unless a physical reconnection is detected.

Tweak the display settings: Settings > System > Display. After switching back to the 770 machine and seeing no display, hit Windows + P and choose Duplicate or Extend — this sometimes reinitializes the display.

You can also try setting the display to “Always On” through Power Settings or disabling fast startup.

Try updating the graphics driver, make sure the latest Intel UHD 770 drivers from Intel’s site directly, not just OEM-provided ones.

[CharlesHTN]

@molan

In my case I ended up connecting a additional monitor I had laying around directly to the RTX card, then simply turning off that monitor in windows.

I don’t recall what they are called, but I believe there are small dongles you can connect that simulate a monitor. I would think one of those would work similarly, and prevent needing to have a monitor you aren’t using sitting there.

[molan]

@CharlesHTN

small dongles you can connect that simulate a monitor.

I have several of those I use them with Pi Devices. the RTX 50xx series doesn’t like them either.

Been there Tried it got the T-Shirt LOL

[zacl]

I’ve updated the drivers on the 770 machine to latest from Intel site and still the same problem. I really need it to work when switching back and forth without any special key presses or steps. It’s at a church with volunteers running it.
I’ve reached out to IOGear to see what they say too. Would using a VGA KVM and a DP to VGA adapter elimnate it? I assume the adapter would trick the display port into thinking it’s always there, like an old fashioned analog VGA?

[Rod-IT]

What is the purpose of the other powerful machine, do people also use that one?

Is one device not suitable for multiple tasks?

[molan]

@zacl

Would using a VGA KVM and a DP to VGA adapter elimnate it? I assume the adapter would trick the display port into thinking it’s always there, like an old fashioned analog VGA?

based on my tests no probably not. but if you already have the adapter you have nothing to lose by trying them

[zacl]

There is a machine for live streaming and a machine for projection software.

[Rod-IT]

Couldn’t one do both, it’s plenty powerful enough.

Do all people need to access both, no option for a second portable screen, mouse and keyboard to avoid the current issues?

[somedude2]

@jollybgood

DisplayPort KVM

Guessing you are at resoloutions where HDMI doesn’t make sense…(it plays better at this sort of thing)

See, it isn’t all about the ID data, there is also copy protection data (HDCP) going between the monitor and the GPU, and it is --supposed-- to break when you do this, so you don’t use a monitor to close the encryption key and then switch to a digital recorder to bootleg a movie…
This is why just EDID emulation doesn’t fix it…

[zacl]

I contacted IO Gear today and I think I’m going to order a HDMI KVM and DP to HDMI adapters. I may end up going some sort of portable montior with a kb/mouse if I can find room. They’ve had this setup with 2 and makes it easier because it separates the uses and keeps the one running the stream from messing with the projection.