how much voltage I should increase while Overclocking MSI GTX 560 Ti Twin Frozr II/OC

I have MSI GTX 560 Ti Twin Frozr II/OC graphic card and the default overclocking figures are 880/1760/2100. I have tried to overclock my MSI GTX 560 Ti Twin Frozr II/OC graphic card and it gives me 970/1940/2300 voltage. With this setting my card stable and graphic drivers do not crash but I think I can increase it more. Please let me know what is required to get more Frames per second more core clock or memory clock and how much voltage I should increase with my MSI GTX 560 Ti Twin Frozr II/OC graphic card. I have Intel core i5 2500K processor. Please give me suggestion for this.

With GTX 560 graphic card you should set core clock to 1000, shader clock to 2000 and memory clock to 2400 and voltage should be 1.1. With this setting your graphic card will run fine. First I was using my graphic card with stock setting and after trying different settings I have finally able to card stable. Right now with this setting I am getting 35.1 FPS which. I think you should also try this.

Yes I will also suggest you to use graphic card with 1000/2000/2400 setting at 1.1v. I was also trying to overclock my card and first I tried 1010/2020/2100 setting which was giving me problems and then I have1000/2000/2400 and then my problem get solved.