I should try djm34 version because I don't get that sort of performance on scrypt with my gtx780ti

For scrypt-jane try to autotune first

djm... it was a EVGA 780Ti Superclocked with Skynet bios. OC was +135 (total 1180.6).
The autotune for YAC works on my 780, so I will try the 750's when I get home tonight, as I have to leave for work in a few.