RAM is the simple answer. It’s really the number of samples in an instrument that counts, so the complexity of the instrument is also a factor. There’s a chart on the NemeSys web site (in the FAQ I think), that outlines the amount of RAM needed to load various numbers of samples. With 128MBs you can’t, for instance, load the entire AO string section.
Of course, polyphony is also finite, especially with LE. You may be able to load more than you can actually play at one time.
Bill is right.
Another important factor is, wether the instruments are in Mono or in Stereo (divide by 2). A whole orchestra might fit into GS with 256 MB RAM, if you use mono samples. This is also advisable because of polyphony.
Thanks Horst! But I hear some drop outs and crackles when I used AO String last time and when I try it with cakewalk 9.0 (usually I use Cubase) i even couldn\'t record inside my sequence because it stop (not just drop out) and I had to use many trick to work it out ( like record digitally to my sampler and transfer back to comp), I\'m not sure what\'s going on.