ok idk if this is because of the motherboard or somthing in the bios, or OS i missed. Windows 7
will only recognize 3.2gb of the 4gb of my kingston ddr3 1333 mhz with memory remaping off, and 2.9gb with memory remaping on. and iff i add my old 8800gt in paired with my gtx 260 for physx, it drops my usible ram down to 1.9gb and the windows 7 performance score goes down to 5.5 from 7.6 only if i add in the 8800gt. hope you guys can help
32bit has severe memory limitations compared to 64bit. It can only handle approximately 4Gb of memory, and every type of memory subtracts from that. Your video cards memory will reduce what is left for available system memory, and adding a 2nd card for physics adds more video card memory which will than be reduced from total system memory.
What mobo do you have? Win 7 don't have the limitation of XP x86. Sometimes, the amount of RAM that you don't have (4GB-3.2GB=800MB) is for address the devices of your PC and for complete the 1GB of your GPU.