Legit Reviews published an editorial by Nathan Kirsch on the future of computer memory and what he believes is the right memory for you.
The old 32-bit processors that we all loved such as the Intel Pentium 4 and the AMD Athlon XP, could not address more than 4GB of memory. While this was an issue the move to 64-Bit computing did away with those concerns. Did you know that the current Intel Pentium 4 (EM64T) and AMD Athlon 64 (AMD64) desktop computer processors can handle 1024GB (1 Terabyte) of memory...The Future of Computer Memory: 2GB+ Review