Pre-built computer keeps bottlenecking during video games?

[phont]

While trying to play video games, I keep running into random graphics lag spikes or just really choppy frames.

I've swapped my video card from a IceQ X Turbo 6950 to a GTX 670 EVGA Overclocked, so I don't think that's what is causing it.

I keep running into these problems on games that I should run flawlessly, regardless of them being more graphically appealing.

Here are my computer specs. Also, this computer is pre-built:

Processor: i5-3570k

GPU: GTX 670 EVGA Overclocked

PSU: 750 Watt Corsair CMPSU-750TXV2

RAM: 8 GB

Cooling: Asetek 550LC Liquid CPU Cooling System (Intel) - ARC Dual Silent High Perfornamce Fan Upgrade (Push-Pull Airflow)

OS: Windows 7 64-bit Home Edition

Are there any programs I can download and use and post my results here to receive help?

Thanks in advance.

 

[lt_dan_zsu]

You can use intel burn test and prime95 to test cpu stability. Then you can use furmark, 3dmark11, and unigene's heaven to check for gpu stability. Use memtest to check ram. If you download this stuff, be careful because some of the sites you get them from have a lot of viruses.