I work longterm, out-of-town projects for my job, and one rack computer and keyboard is all that is practical to travel with and have for a music workstation right now.
My one DAW has EW Silver/Gold, Cubase SX, Kontakt on P4/2g Ram with three (Programs/Samples/Audio) 7200rpm drives. Present small compositions consist of 6-8 Siliver/Gold midi tracks playing realtime live. I'm still learning how to work with software sequencers and haven't yet learned how to record to audio in Cubase. Audio in my world is running analog line-outs from RME multilface to Sony Walkman DAT. With that background, hopefully you can understand why I can't predict if the following is even realistic:
As compositions become larger and more instruments/tracks/libraries are added (wish list is to convert VSL to Kontakt and add KH, SI, Bela, Lastufka, Garritan, SAM, Atmosphere, on and on (did I miss anybody?) etc), what is the feasibility of accomplishing a fairly large composition with all these multi VST's/libs on one machine? My understanding is that when I run out of power, I can bounce a section of midi tracks to audio on my hard drive, and then continue building the composition -some tracks playing back with the less power consuming audio, some still in live sample midi form. And with this process, I "should" be able to continue to work from one computer, building fairly complex compositions and using a variety of VST's/libraries.
Other than the pain/inefficiency/time it takes to work this way, is this one machine scenario realistic? Are there libraries so power intensive that you could not run two channel audio, the sequencer, and at last one live sample midi track, all at one time?