NVIDIA to launch "Maxwell" based GTX 960 graphics card this month
I don't think you needed to change your system definition as only two specific versions of nv drivers were checking if it was installed on a macpro or not. As a general matter, toying with the system def is not advised. Well as long as it worked, that's what matter.
Mine (MSI GTX 960) shows up as NVIDIA Graphics Device 2047 MB in System Report with iMac 14,1 / i5 4570S. So it's also a generic name. The difference could come from sysdef, card brand (what do you have? msi, asus, evga ?) or the fact I use clover, I don't know.
But as I stated in my previous posts, I got similar perf with Unigine on Windows, so it seems that it is fully supported! You should try to run the benchmark with the same settings and compare your score to mine.
