you mean CPU?
1 Ghz = 1.024 Mhz Gpu's or graphics cards you wil never get a 3Ghz gpu(NEVER) in the future YES
there will always be lag on CA(no matter what the system you have)
anyway, I would go for a AMD x2(X3 or X4) with higher than 2.1 Ghz or Intel Core to duo X2
and get a mid ranged GFX card (geforce) GT240, GT250 or a GTX260
I never buy ATi so I dont know alot on them.