I've bought AMD fx-8150 processor recently and since then I'm having horrible problems with its temperature being way too high. When it's running idle on stock cooler the temperature is usually like 33*C but when I start rendering a scene with LuxRender, it hits 70*C in about 40 seconds. It's really disquieting how fast the temperature increases - the increase from 30*C to over 40*C is instant and then the temperature-time curve is more or less logarythmic. I'm using only the stock cooler, but I changed the thermal compound. I'm sure the cooler is installed properly. I changed the fan to a better one (arctic cooling, 120mm fan, ~1400RPM) and it actually improved the cooling efficiency, but it's still way too low to provide stable work. In fact it just slightly delayed the time the CPU reaches insecure temperature.
At the first time I ran a render, I wasn't monitoring the CPU temperature and it probably hit something like 100*C which (thank God) made the system shutdown automatically to prevent burning the CPU. The other reason why it's overheating could be that one piece of 8pin plug which powers the CPU was unplugged at the first time I had been running my new PC (the plug wasn't fully inserted) and my PC wouldn't turn on - could this damage the CPU?
The only other thing I can think about is that the voltage is too high. It was reduced in BIOS to 1.265V (at lower voltage system won't boot) but it's not helping. I reduced it using AMD OverDrive and at 1.25V the CPU is not overheating that much but the temperature can still go up to around 80*C (approximation based on the shape of the curve). Now I don't let it go hotter than 70-75*C since AMD states that the highest temperature for this chip is 61*C.
All the temperatures I provided are average core temperatures measured with AMD OverDrive. I've never overclocked the CPU, I even turned off Turbo mode which would overclock it to 4.2GHz at full load, turning the other 4 cores off.
The other components of my PC are:
Motherboard - Gigabyte GA-990XA-UD3
GPU - Gigabyte GeForce GTX295
RAM - 8GB single card 1333MHz Patriot
PSU - Tacens Radix V 850W
OS - Windows 7 Professional 64 bit.
Please, help me if you can, you are my last hope. I even contacted AMD support and they said that it can be a faulty CPU or cooler. However I want to try all the possible solutions before I send it abroad... I ordered a new cooler and case but I'm having it delivered in a few days. I think it's not actually the problem with the stock cooler because other people are using it and they say it works fine (but loud
I personally don't see how it could be a faulty cooler, especially since you swapped out the fan. See what you get with your new cooler, if heat remains a problem, I guess you'll know it's the CPU. And no, plugging it in with only one of the four pins conneced may cause it not to boot but shouldn't hurt the CPU (at least to my knowledge)
There is almost no airflow since the case is opened. Actually when it was closed there was no difference but now it has to be opened because I was checking if the sensors are not broken using a pyrometer. The case is very cheap and old - from a supermarket PC. I'm getting a new one together with the cooler.