My understanding is that the current 0x17 core does not like the Maxwell chip in the 750ti. The folding@home team is working on a solution, and there's a beta 0x17 core you can try. I am firing up a pair of 750ti's I just acquired tonight, so I'll be doing my own tests with them. if I find out anything useful I'll post it here. In the meantime, search the folding@home forum for '750ti' to see the current discussions regarding it and what progress has been made. getting ready to do that myself, it's been a few days since I checked back there.