915P chipset support 4GB mem?

I have a mobo with an intel 915p chipset. it has 4GB (1GBx4) of 533Mhz DDR2. In the bios it sees the 4GBs, but in my OS which is 64bit linux it sees 3.32GB. Does anyone run 4GB on a 915 chipset and see all 4GB in the OS?

thanks.

okay did some digging around and it seems the 915 chipset is 32bit? so it can only access the 3.2GB Memory. so even though the CPU and OS are 64bit, Im limited by the chipset, how weak. Its just my test system to run vmware on, hence why I put 4GB memory on it, although 3GB is plenty, it just bothers me that Im short 1GB. Think I'll just ebay off all these cheap parts and get some decent ones. end up spending about the same.