MST support for Linux

I was wondering about the current status of 3840x2160@60 FPS with the Linux drivers.

319 and 331 didn’t seem to support 60FPS at that resolution although SST was working fine at 30 FPS.

I’m using this with an Asus PQ321Q 4K monitor and Quadro K4000 card.

Look through the pages of this forum - this topic has been discussed here many times and solutions have been given. 60FPS are supported if several conditions are met and several tweaks are configured.

I have but I’ve not found any relevant hits for “MST”, “tiled display asus” or “3840”.

Discussions tend to be about HDMI which shouldn’t support this frame rate by specifcation.

Enabling MST on the monitor and using DisplayPort should be enough. From what I understand with the Windows drivers it just works.

Could you point to one of the links? I’ve not been able to find any.

This seems to be the only link that is related but instead references Windows drivers (and is on a different forum).

Hopefully this will resolve things.

Unfortunately after going through the link further it appears to not be helpful as the key part is the driver.

Nothing special is needed for MST except for doing it automatically. Unlike on windows nvidia has always supported horizontal spanning on linux (well ok, for the last 10 years I have been using their video cards they have).

Its over display port instead of DVI but I basically have been using MST (horizontal) spanning on my 4k displays on linux since 2005.

Here is a picture of my older model 4k monitor getting 60hz @ 3840x2400 (higher than 3840x2160), which required genlocked inputs via two dual link DVI driven off a dated geforce GT 8800 (image is from 2010):

The linux drivers may not do it out of the box for you but it should be extremely easy to set it up yourself as long as each input is detected and can be used like any other DFP device. For quite a while now nvidia drivers have supported MST (more for display hubs I believe) so it should work just fine if you know what your doing.

I think I missed you actually had one of these displays. Are you not getting any picture at all or is it just showing up as two 1920x2160 when the monitor is set to MST mode?

jagannatha: Enable mst and run X with -logverbose6 and post your xorg.log or nvidia-bug-report and I will send you an xorg configuration to try.

I can’t find the driver initial support was released but I want to say it was pre 300. Anyway:

319.32 : Fixed a bug that could cause the X server to crash after power-cycling displays connected behind a DisplayPort 1.2 Multi-Stream Transport hub.
331.13: Fixed a bug that prevented nvidia-settings from creating display device configuration pages for newly connected DisplayPort 1.2 Multi Stream Transport downstream devices.

I would suggest atleast 319.32

Thanks houkouonchi.

On Friday I was able to get the display to show as dual 1920x2160 by first plugging in a monitor on the DVI port and leaving the Asus plugged into one of the DP ports.

I did notice vertical tearing where the two controllers would split responsibilities but it’s been a relief seeing it run at 60 Hz.

I appreciate your post, and I’ll look into this further Monday.

ok well if you send me your -logverbose 6 xorg.log I can make some suggestions or just the nvidia-bug report thing which will have that and more would work as well.

I’m having issues with startx in verbose mode. However, I’ll see if I can get an updated firmware from Asus before looking at logs. I’m seeing the same issue as the post I referenced (monitor needs to move from SST to MST and can’t boot in MST) so perhaps if the monitor firmware gets updated I’ll be able to just boot into 4K@60.

I doubt its just going to work. I really need logs when the monitor is in MST modes to help. loverbose 6 would be nice but its not required.