SamTherapy is correct on AMD but I use them exclusively. If you can afford 2 gigs of RAM. then consider this when choosing. There are several "speeds" of RAM avail. Make sure you dont get sucked into gettin the cheap on sale "single sided" DDR for your P4 board. Pay a little extra and get quality, double sided RAM with the minum MHz of your motherboard or higher. Here's why: If your P4 Mobo is a 400 Mhz (or 5 hundred and up for Pentium), then usually the buss speed of your Ram is what everything else will run. If ya get PC2700 RAM (333MHz). this will limit your system to run at 333 instead of it's intended 400, or 500 up.. (I have no idea what your new system will be or is)... Example: If your P4 Motherboard is an RDRam board, (pentium) then I dunno. just pay attention the the RAM "speed" as well as the "size"...