What MOST people can expect:
750 = 260khs
750ti = 300khs
I can likely go more on the 750s, but my 750ti's seem to max at about 305-310 now with the newest cudaminer and high overclocks. Previously I was only able to get 288-295 consistently.
What do you mean by "newest cudaminer"? I'm slowing closing in on 300khs with a 750Ti using the February release on stock bios. Each day I push the clocks up a bit more and then leave it to test for stability. I'm still on the February release because I also have a 650 Ti BOOST in the same machine and its performance went down with newer versions due to the known CUDA library issue. May have to try running two instances of cudaMiner (one old and one new) if the newer version can take the 750 Ti higher.
I believe it was compiled from the sources updated 4/15. I think Christian mentioned it should help the pcie bandwidth issue when using risers. It seems to have helped a little on my amd rig and my socket 1155 intel, but it helped most on my 1150 i3 rig with the EVGA FTW cards with raised TDP. Went from 1765ish to 1855ish I think.