Running 2 monitors off one GPU?

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UBT - Timbo
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Running 2 monitors off one GPU?

Post by UBT - Timbo »

Hi all,

A little while ago, I got a new GPU...it's a NVidia GTX970 and it works fine. (It replaced my GTX590 which I offered for sale on here, but that's now in a box, and will be put to some other use at some point).

I've been using a 32" Samsung widescreen LCD monitor and everything has been tickety boo with no issues. The supplier of the monitor let me know he had another one at a silly price. So, I got it.

Now, the GTX970 has 2x DVI, 1x HDMI and 1x Display Port outputs. So I thought I'd run 2 DVI cables - one to the 1st monitor and one to the second.

But despite trying to use the NVidia Control Panel app, I could not get them to work.

I read a few reports that it's better to run 1s Display Port output to one monitor and then DVI to the 2nd.

Does anyone have any experience of running to monitors off a single NVidia card?

regards
Tim

(For the time being, I have a spare GTX560 so I've installed that and re-installed the NVidia drivers and that works fine. The only downside is that the GTX560 is "found" by BOINC and hence it tries to crunch tasks, but the fan noise is unbearable. !! So, I need to stop BOINC from using it - that's done by the following:

The cc_config.xml file needs tweaking if only ONE GPU is to be used:

Code: Select all

<ignore_cuda_dev>N</ignore_cuda_dev>
rem Ignore (don't use) a specific NVIDIA GPU. You can ignore more than one. Requires a client restart. Only used in 6.10.19 till 6.12.41.
<ignore_intel_dev>N</ignore_intel_dev>
rem Ignore (don't use) a specific Intel GPU. Requires a client restart.
<ignore_nvidia_dev>N</ignore_nvidia_dev>
rem Ignore (don't use) a specific NVIDIA GPU. You can ignore more than one. Replaces <ignore_cuda_dev/>. Requires a client restart.
Example: <ignore_nvidia_dev>0</ignore_nvidia_dev> will ignore the first NVIDIA GPU in the system.
scole of TSBT
The Scottish BOINC Team member
Posts: 46
Joined: Wed Dec 07, 2011 12:00 am

Re: Running 2 monitors off one GPU?

Post by scole of TSBT »

I run 2 monitors off a GTX 1080 but it only has 1 DVI port, 1 HDMI and 3 Display ports. I use the DVI and HDMI. Don't recall that I had any issues. Don't need to change anything under the desktop settings/properties do you? What OS? If linux, which desktop? What model 970?
UBT - Timbo
UBT Forum Admin
Posts: 9673
Joined: Mon Mar 13, 2006 12:00 am
Location: NW Midlands
Contact:

Re: Running 2 monitors off one GPU?

Post by UBT - Timbo »

Hi Steve,

Thanks for your reply.

It's a Gigabyte G1 Windforce GTX970 c/w 4Gb memory using Win XP Pro (yes, I know !!) and the monitors don't have Display Port...so it's either VGA, HDMI or DVI.

I tried a couple of DVI to HDMI cables: DVI (at the 970 GPU end) and HDMI (to each monitor). Only one monitor worked, plus it defaulted to a particularly low resolution of 800x600, making use of the NVidia Control Panel very difficult (as that CPL doesn't scale, and the buttons you need to click on are at bottom right corner, which you cannot get to, as the window isn't resizeable...).

What is also strange is that individually, the monitors will run at a ludicrous res - something like 2560 x 1440 or so using a single DVI<>HDMI cable. But when two are in use (1x GTX970 + 1x GTX560) the max I can get is 1920 x 1080 32bit @ 60Hz (as shown in the Control panel box - no higher res are listed :-) ) and even then some of the text displayed isn't very clear.

So, I've downscaled to 1600 x 900 and that seems fine for now.

regards
Tim
scole of TSBT
The Scottish BOINC Team member
Posts: 46
Joined: Wed Dec 07, 2011 12:00 am

Re: Running 2 monitors off one GPU?

Post by scole of TSBT »

Have you tried the instructions in this post?

https://www.microsoft.com/resources/doc ... x?mfr=true
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