I have had my computer for a good 2-3 years now and have been trying to play some newer games on it. I upgraded the GFX card to a nVidia 9800 GT 512 MB card and added a 800W PSU and expanded to 2 GB of RAM. Now i want to overclock the system a bit. I've heard recently that mixing memory brands is bad, but I did it a few years ago when I had absolutely no knowledge of computers. I've done a little research on my own, but don't want to hurt anything vital. It seems you might need some of the information about my computer. Some specs: Computer: Gateway GT 5220 Memory: 1024 MB stick of Kingston. I know they're DDR2 but idk what the number after that is.. I see a few numbers that might help in CPU-Z which are PC2-4300 (266MHz) 2 sticks of 512 MB of Samsung (same numbers as kingston) CPU & MOBO CPU: AMD Athlon 64 X2 4200+ "windsor" MOBO: (idk anything about it so i'll list everything i can find and hope someone can help) Manufacturer: Elitegroup Model: c51pvgm-gb NVIDIA GeForce 6150 AM2 uBTX 1394 Motherboard ECS C51PVGM-GB Version 1.0 System Board NVIDIA GeForce 6150 DDR2 DIMM sockets support 533/667/800 MHz modules I'm attatching screen shots of information about my system. I hope they're of some use. Thanks in advance!