Lag on my game PC

[BIOLOD]

Hello, i just bought a custom build game pc. all of my games play fine at the highest settings without any sort of lag. but when i play Borderlands 2, my pc just starts lagging. i find this very strange because i have a great pc.
here are my specs:

Graphics card: asus AMD Radeon HD 7970 3GB.
RAM: 8GB
Cpu: AMd fx-8120 8-core black edition.

I would really appreciate if someone can tell me why my game is lagging.

btw. i have windows 7 64-bits and i have a 32-bits borderlands 2 version.

 

[Kamen_BG]

Well actually you've got a great graphics card but your CPU isn't that amazing.You need to overclock it a bit in order for the game to stop "laging"
http://static.techspot.com/articles-info/577/bench/CPU2.png
Your CPU is about as fast as the FX 8150 at 3GHZ so if you overclock it a bit you'll gain a lot of performance.And since your CPU's a black edition overclocking is extremely easy.
Just increase the multiplier to 20 and it'll run at 4 GHZ.But before you do that make sure it's cooler is up to the task.That means that you need an aftermarket cooler first.

 

[Jay-Z]

Yeah, the 8150 needs serious overclocking to be viable.