I've just purchased a good computer (I hope), I picked the components myself and there good as... but, due to having to wait ages before it con be ordered I went with Memory that I now know has a fairly slow recomended CL3 as apposed to CL2.5.
How much performance am I losing by using slower timings?
Its good quality (yet budget) Kingston valueRAM, DDR400, 512MB, PC3200.
I want to play all the latest games confidently with my awsome AMD Athlon 64 3200+ CPU and NVidia GeForce 7600GS Graphics card powered by PCI Express.
Is overclocking a good idea with my aircooled system? Its a Raidmax Saggita Gaming Case, has two 120mm fans in the front and back, a 90mm fan on the side and stock CPU fan (not that great I know).
Motherboard: Asus A8N-SLI... socket 939 duh!

Ok, 3.0 -> 2.5 will give you about 1-5% max difference, but you will sacrifice possible system instability which in my opinion is not good. Yes, you can overclock on air, but you will need better ram most likely. However, what do you really want to do that you think overclocking will accomplish that your stock settings will not besides lower the life of parts, give possible system instability, and increase the heat of the parts as well as drain more electricity than necessary?