Hi Sun --
You're ok with both utilities on the same machine. If I've played catchup properly, am I correct in my understanding that at 1228 your performance is less than at the default 1175? That's actually not possible, but I think I know what it would be if it's showing that. The 762x's vary depending on what the x is. Here on 465's on 7623's I'm 4 seconds under 9 minutes per frame, give me a 7625 or 6 and I'm 6 seconds over 9 minutes a frame.
I have to assume you'd be wondering what this overclocking nonsense is all about if your frame times were actually slower than before you started many hours ago. ;-)