2 GPUS = Bad idea?

I thought I would try installing my older Geforce GTX 760 for GUI and use my Geforce GTX Titan for Compute.
Running 12.1 Studio.
I have unchecked Use Display GPU For Compute.

I am getting any advantage from this setup?

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I think you might especially if you're running a couple 4K monitors

a little bit, the gpu does not have the load to do the monitoring.

So as it stands, I am not hurting my performance then?

So I assume to really get better performance I would add a second GeForce GTX Titan GPU and then check the
"Use Display GPU For Compute"

No as long as use GUI for processing is set to off. if you had a very old weak GUI gpu It would hurt. 760 is recent and good GUI gpu. But programs like avid and premiere will use the 760 so they will suffer.
Yes a second Titan x would help. But not as much as you would think. It's very powerful on its own.

Paul,

Thanks for the explaining it to me.
I will run Sascha Haber's Standard Candle test to, see if I am getting any performance boost by dedicating my Titan for processing
Sounds like by adding a second Titan the ROI is not to good.

My biggest bottleneck is using "optimize media" which I know has nothing to do with GPU

Strong gpu + weak CPU limits power. Both need to be powerful for full benefit

The other advantage of using the older GPU for GUI only is that you have the full VRAM of the Titan available for compute. If you use GUI GPU for compute, you will limit the amount of VRAM Resolve has to the amount supplied by the 760.

yes, dual gpu wireless well only if the two gpu are twin, otherwise use the lesser four gui and the titan for computation

Definitely seems to be! I tested using the "nVidia GPU Utilization" utility.
It displays a live graph of the usage of both GPUs.
GPU#1 is a GT 740.
GPU#2 is a GTX 980Ti.

I started up Resolve Studio (latest update of version 12) on Windows 7 Pro.

I loop played a short ProRes 422 LT clip:
On playback GPU#1 20%.
On playback GPU#2 5%.

I added a NR node (Large/100%) with node cache on:
On playback GPU#2 peaked at 95% then settled to 20%.

I turned the node cache off:
On playback GPU#2 peaked at 95% then settled to 65%.

I went to Preferences and set ON: "Use Display GPU for compute"
I restarted Resolve.

I loop played the same ProRes 422 LT clip:
On playback GPU#1 (980Ti) 30%
On playback GPU#2 (740) <5%

I added a NR node (Large/100%) with node cache on
On playback GPU#1 (980Ti) 100% peak then 20%
On playback GPU#2 (740) 50% then <5%

I turned the node cache off.
On playback GPU#1 (980Ti) 100% (no drop)
On playback GPU#2 (740) 20% (no drop).

I am not really sure if that is the performance which the developers intended.

I am also not sure what the point of it is/was intended to be.
I see no use for it.

Maybe someone here or at Blackmagic knows why (or in what circumstances) one would want to use that setting.

Hmm maybe the only time you see any real advantage is when you use 2 identical GPU's
I guess using an older GPU to handle just the GÚI and the second faster GPU used for compute really does very little then.

Apologies!

I did NOT mean to say that I thought using two GPUs is a bad idea. It is not.

What I meant to suggest that might be a bad idea (based on my measurements) was turning on the option "Use Display GPU for compute".

I am not sure why one would want to do that as it seems to bring no benefits - but rather the opposite.

Maybe BM (or someone here) knows a good use for that setting.

[Dwaine Maggart]

If you had, for instance, 2 Titan-X cards in your system, and one is driving the GUI display, you would want to enable the "Use Display GPU For Compute" option to utilize the display GPU as an additional processing GPU.

It would be recommended that you only enable this if you have identical graphics cards.

or only one card

[Dwaine Maggart]

It's automatically enabled with only 1 graphics card.

does it hurt enabling in this case?
or just redundant. Like me.

[Dwaine Maggart]

It does not hurt. But it's not needed. No problem enabling it with one card.

Learn something every day.
Well if I don't see you Merry Christmas and happy new year!

[Dwaine Maggart]

Same to you Paul!

Dwaine,
Do you know if adding a second GPU will help at all with the media optimize operation?
I have a lot of 4k h.264 video that I first optimize.

Dwaine,
Do you know if adding a second GPU will help at all with the media optimize operation?
I have a lot of 4k h.264 video that I first optimize.

i don't think so, that is cpu load for the h264

[Dwaine Maggart]

Walter is correct.