Just got a 9th GTX 750 Ti. Decided to try a different brand this time and I regret it. Maybe I just got a dud, but this new PNY GTX 750 Ti I got uses slightly more watts for less hashes than my Zotacs.

Max stable overclock Zotacs on Yacoin: 3.41kh/s
Max stable overclock PNY on Yacoin: 3.27kh/s