Windows 7: "new" pc: CPU overheating

Hi, today I built a "new" pc with used parts which I found. It has got:



Asus P5Q-Pro motherboard
2 GB DDR2
Intel Core 2 Duo E6300 @1.86 GHz (65nm)
ATI Radeon HD 4870 X2
Nilox 600W PSU

I'm cooling the Core 2 Duo E6300 with a standard Core i7 3770K cooler (which I don't use), but it causes my CPU to overheat after 3 minutes running and the system shutdown (overheat at 70°C, sometimes 85-90°C)....

Now i decreased the CPU speed to 1.4 GHz and it seems to be stable at 58°C... which is a very high value since I'm downclocking the CPU.
I bought the Asus P5Q-Pro because, with a good RAM, it can push the E6300 up to 3 GHz, increasing a lot the CPU performance... But now I'm unable to run the CPU up to 1.4 GHz
Please can you suggest me a good socket 775 CPU cooler?

(also the CPU has got only a few thermal paste... could it be a problem?)

Can you post pictures of how the set-up is... set up?
Is the heatsink applied properly? Is it loose?
How much thermal paste is there? Did you replace it or just put the heatsink like that?

the heatsink applied properly, but the the thermal paste is really a few... I didn't replaced it... should I?

Yes, you should always replace thermal paste if you are changing the CPU it is going to be placed over.
Im sure the TIM on that heatsink is dried to a crust.

Replace it, you should see a good difference.

ok, tomorrow I'll replace it...

anyway, is the standard Core i7 3770K cooler a good one? it looks like this one: http://www.legitreviews.com/images/r...oundup-027.jpg

As standard CPU coolers go, it's reasonable. My cooler is the same as that, and I have overclocked my CPU to 4.3GHz with SpeedStep enabled (so the CPU only runs at the speed required for the current load).

You should be fine with that one. Make sure that the old TIM is removed completely from both cooler and CPU and then carefully squeeze a small blob of new TIM to the top of the CPU - not too much - and spread it across the surface with the edge of a plastic card so that the surface is covered (follow any instructions that came with the TIM). Reseat the cooler, and ensure that it is securely fastened to the motherboard. Don't forget to attach the fan lead to the CPU fan socket on the m/b.

For serious overclocking, a better cooler will be required. If you choose to go along that route, ensure that it is compatible with and will fit in your system. Follow the installation instructions that come with it.

I ordered the thermal paste, tomorrow I should be able to replace it... Anyway, reducing the VCore in BIOS now I'm able to run the CPU at 1.9 GHz...

I used Arctic Cooling MX-2 thermal paste for my processor which in my opinion is one of the best thermal paste out there in the market .

Arctic Cooling MX-2 Thermal Paste: Amazon.co.uk: Computers & Accessories

thank you...

Now I'm running the CPU at 2.5 GHz with 1.25 Vcore, and it is stable at 55°C... The performance difference is impressive with only 700 MHz overclock (I tested it in games), and CPU WEI increased from 4.8 to 5.9...

This CPU really rocks