Fact: Piano sounds with many notes and sustain pedal on seems to be the most difficult patch to play in GS.
If you add on top of that more instruments, chances are the HD will not be able to sustain the stream of dat.a needed. Pops will occur.
Hipotetical solution: What happens if I put the piano in a disk and the rest of the patches in another fast one? That way GS would stream a more \"equalizaed load from the Hds. Anyone did something like this?
disk1 = OS
disk2 = all samples
disk3 = Bosendorfer 1.5gig piano
No pops even at 160 polyphony (not realistic, but for testing purpose).
I also tryed with very long samples (30sec. or more samples and lots of them) After about 64 differents long samplews playing at the same times from one disk, i get pops. So the trick was to put a bit less, but split on to disks. Example: 50 differents samples on disk2 and 50 other different samples on disk3, so instead of playing a max of 60-64 samples, i can reach 100-110 differents samples using two disk.
So, in conclusion, yes the harddisk is usually the botleneck.