I am not sure I am in the right spot or not. I have a question about how to select the right memory for new motherboard. For example, I am looking a motherboard, and I do see some spec. One example is EPoX EP-MF4-J Socket AM2 NVIDIA nForce4 4X ATX AMD Motherboard and the spec for the RAM is DDR2 800 or other mobo that have DDR 600. I like to know will the mobo that have DDR2 ram will work on DDR2 and/or DDR Ram or just the DDR2 ram? Another question is the number after the DDR/DDR2. Let say 800 is the max number but I can use any lower number. For example for DDR 600, can I use the DDR 266? I am researching the mobo/ram thing since my current cpu is getting out of date when it come to gaming.