Ok this is my first OC. Trying to get my Q6600 SLACR to 3.0 Using this to cool it Scythe SCKTN-2000 100mm Sleeve "Katana 2" CPU Cooler - Retail
My motherboard is ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard - Retail
So I overclocked it to 3.0 and then ran Prime95 for 8 hours while I slept. When I woke up I was pleased to see that it had no errors but when I checked the cpu temp with the ASUS AI Suite that came with the motherboard the CPU temp was 89-90C. That seems very high so i stopped the test and restarted. When I checked the temp again it was 50c which seems high for doing nothing. Was this just still hot because of Prime95? I had to go to work then so do not know if it would have continued to drop in temp.
Is the cooler I have a decent one? Is the program I used to check CPU an accurate one? any tips or suggestions would be greatly appreciated. Thank you.

I would check the temps with coretemp or realtemp.... if the temp's are still high with core- or realtemp i would check if the cooler is seated well... maybe ur giving it too much voltage???

I agree on the Voltage - Make sure it's not set to "Auto".
That generally pumps the voltage much higher than necessary.

Along with the CPU cooler, you need to make sure the case has proper cooling. Otherwise the air in the case just gets hotter and hotter and the CPU fan will eventually do very little.

Thanks, I will recheck the temps with those programs.
The program I used also said the case temp was 39C So it seems like there is decent cooling for the case. Or am I mistaking?

I'm with zenmaster. Never underestimate the value of having good air flow, both in and out of the case.

One thing I have done in the past is to take a can of compressed air upside down and blow it into your tower through the front intake fan. It creates a visual way to see how air flow occurs in your tower. The only catch is that you have to have a window in the side so you can see how it goes without disrupting the natural air flow by having the sides off.

what's your voltage at? you probably set voltage too high. for 3.0g, i only get 1.2v, and CPUz show vCore 1.16v, and idle temperature of 38C.

Well what a difference voltage makes, I lowered it from 1.3 to 1.2 and the highest temp i got was 66c. Thank you all for your help.