Obviously more is more, so if you've got the cash go for it. And by that i mean mac and pro-tools
However if you wanna stick with PC's and then i'd recomend any of the new athlonxp or pIV will give a LOT of tracks.
These days multiple tracks next to NO processing power or hard disk speed (providing its 7200 min which all are i reckon now). The drain on CPU is FX and even more so Virtual Instruments.
Put it this way i can get 40 mono tracks of audio running smoothly on a PIV 1.6 ghz with 256 RAM and a 7200 60 gig drive. PROVIDIng there is no procesing added.
Keep in mind my system specs above and i'll give you a typical project of mine and what i sensibly run.
HALion virtual sampler - triggering wizoo 24bit stereo yamaha acoustic drum samples and Claude Bessue(sp?) String Samples.
2-4 tracks of
acoustic guitar
4-8 tracks of
electric guitar
Either 1-2 tracks of bass guitar OR midi track of bass(s) off my yamaha synth on the soundcard
1-4 tracks of drum loops, sound fx
2 main vocal tracks
2 harmony tracks
Virtual Instruments soft synths NI B4 organ, Absynth, FM7
I put compression and softclip and gating on nearly every audio track and i'll have reverb, chorus and delay in the send returns as standard.
This lot puts the CPU load at 45-55 percent and will run smoothly. IF and this is a nice big IF!!!! you are careful with the disk space on the drive.
This is something i've discovered over the past couple of setups i've had. Say you have a 60 gig drive then never fill it past 30 gig, and keep it de-fragmented as possible. The more full the drive gets the harder the disk hs to work to pre-load the audio data into memory and if your arrangement suddenly kicks in from a couple of tracks to say 15 then its gonna mess up. By keeping the drive under half full and de-fragmented you get the best performance from it and far less mess ups.
David