I'm not sure about your phone, but I rooted my xperia x10 using "Superuser v2" and use SetCPU. I also use SD speed Increase and Chainfire3D. All great apps. I can't overclock my cpu unfortunately but I can set profiles so it sits at 100% cpu speed all the time and doesn't go into powersaving mode. I found it made a big difference to performance, everything is instant but battery life drops quite a lot (But I also have a powersaving profile for when i'm not playing games or using heavy usage apps).