X11 perf on one 750 Ti (development version)... Be afraid AMD.
[2014-05-12 00:43:33] thread 0: 3670017 hashes, 2698 khash/s
[2014-05-12 00:43:33] Total: 2698 khash/s
[2014-05-12 00:43:42] thread 0: 13107201 hashes, 2646 khash/s
[2014-05-12 00:43:42] Total: 2646 khash/s
Brutal.
I'm shocked.