Displayport Switchbox / resolution problem?

NormAtHome · 09 Aug 2015

In my home desktop setup, I have four systems attached to a StarTech displayport KVM switch, which I use to switch back and forth between computers when necessary and the rest of the time I just work on them them using UltraVNC.

I just upgraded a Windows 8.1 machine to Windows 10, I use this machine mostly for processing data / video encoding etc; when I had the KVM switch set to that computer I set the resolution of the screen to 1920X1080; then when I switch back to my main computer the resolution of that computer reverts to 1024X768 and when I connect by VNC if I attempt to manually set the resolution back to anything higher I get a message that says "The display settings could not be saved. Please try a different combination of display settings"

I also tried switching the KVM switch to that machine, setting the resolution with VNC disconnected and rebooting; logging in and then switching back to my main computer but still the same problem happened. I haven't had this problem with Windows XP / 7 / 8.1 / Server 2008; is there any way to overcome this problem and get the screen set to a resolution higher than 1024X768 when I'm not switched to the Windows 10 computer and only connected by VNC?

Btw, the computer in question has an Nvidia Geforce GTX 570 display adapter and I have the latest driver available from Nvidia.

- Norm

mikeOttawa · 10 Aug 2015

I have this same problem since my 8.1 machine upgraded to 10. I cannot keep a resolution higher than 1024/768 on the windows 10 machine when connected via VNC. I also tried TightVNC. I have an nVidia 960 with the up-to-date driver as well.

batlhilz · 11 Aug 2015

you guys have replugged the KVM after you did the installation of win10?

mikeOttawa · 11 Aug 2015

batlhilz said:

you guys have replugged the KVM after you did the installation of win10?

So yes - If I connect a display, the resolution changes to match the physically connected display (even via VNC). After a reboot (with the display disconnected) VNC reverts back to 1024x768.

batlhilz · 11 Aug 2015

can you download moninfo.exe and grab a pic what it shows for you? i dont understand why it wont save the EDID information that it once grabs. however, im not too familiar with the VNC so i dont prolly understand the whole problem here :)

NormAtHome · 11 Aug 2015

Batlhilz:

Yes, I've tried that and no it didn't make any difference.

Please note that the DisplayPort switch I use is a budget $200 switch and not one of those $1,000 switches that maintains a signal to the computer that there's a monitor there when switched to another computer. That kind of switch is totally outside my budget.

I'm aware that there's a major architectural difference between 15pin VGA, DVI and DisplayPort; there's a very long discussion about DisplayPort and problems using dual monitors here: Disable detection, how? but the problem that I'm discussing here was not an issue with previous versions of Windows and has only become a problem on Windows 10.

I've also discovered that things seem to be fine when I use Remote Desktop, but RDP create a virtual desktop and does not connect to the existing desktop session and I'm not sure in my case what extra resources that requires or if doing the processing I used to do on Windows 8.1 will take a performance hit while connected by RDP.

- Norm

NormAtHome · 13 Aug 2015

batlhilz said:

can you download moninfo.exe and grab a pic what it shows for you? i dont understand why it wont save the EDID information that it once grabs. however, im not too familiar with the VNC so i dont prolly understand the whole problem here :)

I've attached the moninfo.txt file (which I did gather while switched away from the computer in question and attached by VNC) as well as a before and after screen shot of when I attempt to change the resolution when attached via UltaVnc.

- Norm

Displayport Switchbox / resolution problem?