I’ve got 1070 + 750, while rendering through f12 works perfectly (2 tiles at the same time), I have problem in viewport with cycles, basically the viewport cycles only renders half image, the setting panel show both CUDA devices are for display, it doesn’t seem to be a way to config which card is only display, what I want is for viewport to only use 1070 while for f12 render to use both, is there a work around? I use 2.78c, cheers.
Both cards say ‘display’ in the options menu but you can safely ignore that.
The card that you’ve not got hooked up to your monitors should be one used for rendering(both viewport and render)
So in your case I’d be using the 750 for monitors and using the 1070 for rendering. Only select both when you’re going to render and you don’t need to use your pc in the meantime.
This is what that setup looks like in v2.78.4(a buildbot version)
I use that 2.78.5, official version (2.78c) doesn’t have this problem so I guess its just in this build, not a big deal though I’ll just have to remember to tick both on in order to render with both.