Render speeds with 2 different cards

[bendingpixels]

Hi all, I just got a new GTX970 running along side my GTX670 in my win7 PC with 64 gig ram.

In the attached image, you can see render times for the same scene with both cards, and each card separately and with priority set for both or one.

Question: Why is the 970 only render nearly as fast as both cards working together?

Thanks!
rob

[atome451]

Difficult to say like that.
You should try the Octanebench for a better evaluation : https://render.otoy.com/octanebench/

[bepeg4d]

Hi rob,
how many monitors do you have?
Priority must be used only for the card with monitors attached.
looking at the average OctaneBench results, you should expect almost a 50% boost when using the 970 with the 670
https://render.otoy.com/octanebench/res ... ingleGPU=1
Try to use GPU-Z or something similar to monitor the GPUs temperatures
Maybe one card is overheating the other?
ciao beppe

[bendingpixels]

Thanks for the replys all! I didn't realize that the priority setting was for the system monitor. I'm running 2 displays off of the GTX 670. So I'll set priority for that!

I'll try to get the benchmark running tomorrow.