When OC'ing (I have an i3 530 btw), should you always manually change the voltage? I kept mine at auto, and I raised my bus speed from 133>137 (multiplier is 22) and now it's hitting 65 degrees when using prime95. According to the intel website the max temp I should let it become is 72, so I decided I'll only let it hit 65 for some room. Is only allowing it to hit 65 a good decision?
If I keep my voltage at stock, what's the highest I can raise the bus speed to before it becomes unstable? If it does become unstable, can this permanently damage my cpu? Is raising the voltage the one that increases the temperature, or is it raising the bus speed that increases temperature? Or is it a mix of the two?
One last question, would re-applying thermal paste and buying a cheap CPU cooler make the temperatures noticably lower?
If you raise the voltage way too high, it will start to rapidly reduce the lifespan of the chip, if you want a cheap cooler, grab a Coolermaster Hyper 212 Evo air cooler, they are very cheap but get the job done, but they are a pain to install.
It depends, you should set the voltage manually to get it as low as you can while it still being stable.