Please Read, it is related to this forum section.

System Specs:
CPU: Pentium D (dual core) 3.2Ghz
Video Card: Evga 8800GTS 320MB Superclocked
Ram: Kingston KVR667D2N5/2G (one stick of ram)
Motherboard: Asus P5QL/EPU
Hard Drive: 250GB Western Digital (IDE)
OS: Windows XP Media Center Edition 32bit
PSU: 600w OCZ SilentxStream

I been using this setup for about 2 years now and it ran games just fine.

About 6 weeks ago my old motherboard (Asus P5PL) gave out. I had to buy a new motherboard and ram (my old ram was incompatible with the new motherboard), I also reformatted my hard drive and reinstalled Windows along with replacing them. Now when I play my games (such as Call of Duty 4 and Battlefield 2 titles) they run poorly even on very low or minimum settings. I used to run them at near max settings pretty smoothly before with my old motherboard. I tried changing my video drivers three times now, but nothing's changed.

Specifically what happens while playing Call of Duty titles is the fps will go up (70+ frames per second) if I look away toward a wall or floor, but when I look to where everything is at and all the action it drops pretty badly (30-50 frames per second), even on minimum settings. I run my games at either 1024x768 or 1280x1024 so it shouldn't be straining the video card that badly. But as said, I used to run the games pretty smoothly all the time before at near max settings. Every game has generally not so great frames-per-second compared to my old motherboard.

Side notes:
*DirectX is up-to-date.
*All my drivers are installed.
*CPU temps are 39c at idle, 55c while playing BF2, and 60c while playing CoD4.
*GPU temps are fine
*Windows is a fresh install.
*Not too many apps running in the background.
*Ran chkdsk fine.

Some people said that because I'm running one stick of ram that, that might be the culprit behind the lack luster gaming performance. I had multiple sticks of ram on my previous setup. Could two sticks in dual channel be that much of a performance difference than one stick in single channel. The frequency of the ram module is 667Mhz by the way.