Voltage seems alright. I reach 3.6GHz with my Q9450 at 1.29V and 3.8Ghz at 1.33V.
Given how the Q8300 is a lower-bin processor, looks like your voltages are right where they need to be. I agree with Dork, you need to load the PC for at least an hour with specialized software.
Gaming doesn't qualify - at most you'll load the CPU to 60% with the heaviest games. You need raw math. :rtfm:
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