tlwAvoid 5400rpm drives for audio use, they're too slow. You need 7200rpm or better. Preferabely SATA3, and even better good SATA 3 SSDs, at least for the system drive. SSDs make things generally much "snappier". For the processor I'd say go for an Intel i7 Ivybridge rather than an AMD anything. AMD might be cheaper, but that's their only advantage. No need to go to the bleeding edge/most expensive/latest model with cpus though, that might add some power (which you'll almost certainly never need) but also just adds cost and means more heat to get rid of, which means more fan noise. Go for at least 16GB of RAM rather than 8 if you can afford it, especially if you use loads of samples or synths that are sample-based. Make sure your chosen motherboard has USB2 sockets as well as USB3 - loads of audio-related hardware doesn't get on with USB3 (even though the sockets are meant to be backwards-compatible).