My new PC and some problems

[saurabh_taurian]

Hi everyone. I just bought a new pc with following configuration

Inter Q6600 2.4 GHz
Gigabyte Ga-P31-Ds3L
2GB DDR2 RAM (800 FSB) Patriot
XpertVsion HD 4850 512MB
Cooler Master Cabinet Elite 330
Corsair PSU 450 Watt
250 GB WD HDD

The normal temperatures of my CPU and GPU are very good. At idle my CPU temperature hovers around 38 C and GPU 44 C which is very good for a card like HD 4850. XpertVision has its own Heatsink and fan installed on it and i found it very effective. It's very silent too. The problem i'm facing is that my PC freezes up freequently. While I'm playing game like CALL OF DUTY 4 or CRYSIS i noticed that my GPU temperature goes up to 55 C which is very good under load and Cpu temperature also hovers around 53-55. Its is happening quite often that this problem is arising.....even while i was working with some softwares like After Effects, fusion etc etc. Sometimes it freezes just like that wile doing a normal amount of work.
Can this be due to BAD ram or something coz i think My temperatures are very good. I recently installed a 120mm coolermaster fan in front of my Cabinet just to provide better airflow coz i thought it might be heating issue but the problem still persist. Please help me as what can be the problem for freezing up??

 

[ghmage]

The PSU sounds pretty low on wattage.

 

[saurabh_taurian]

The PSU should not be the reason for that coz dor the first week i used 600 Watt cooler Master PSU and i was still facing the same problem with it.

 

[ghmage]

If you have not already done so, you could test the RAM with an .iso of mentest86+

http://www.memtest.org/#downiso

Usually for me it is heat or power that causes hard lockups, but you seem to have covered those bases.

If your RAM tests ok you might try another graphics card.

 

[saurabh_taurian]

Another quick question. One of my friend owns a XFX Nvidia 8800 GTS 320 MB and i have XPERTVISION HD 4850 512 MB.
But he's getting a better frame rate in almost all the games than me. What could be the reason?? His card and CPU temperatures are running higher than mine so heat is not an issue. Though he has and AMD ATHLON 6000+ processor and 4 GB ram where as i have Q6600 2.4 GHz and 2GB ram. Does that makes a difference??