I have 2 GeForce GTX 750 Ti GPUs in my system (no SLI), the first has 3 monitors on it and the second has nothing connected. Under the system tab in user preferences I selected the second GPU to be the only compute device. However, when I click render it doesn't seem to be doing anything on the second GPU, only the first. My situation is similar to this question but it didn't provide me with an answer. Multiple graphics cards. Is there a way to designate one as compute device only?
Here's a screengrab of the preferences and the GPU load using TechPowerUp GPU-Z while a render was going. The monitor is showing that there is no load on the GPU when there should be something. I've tried switching which GPU was selected, even selecting both and got the same result, it never uses the second GPU.
Is this expected behavior or maybe a bug? Is there another setting I need to look at changing?