EDIT: I obviously didn't read DG's post before answering... [:)]
Q1: The default is a maximum 2GB per process period. With the /3GB boot switch and an LAA application (as discussed in the first post) you're able to get it up to 3GB per user-mode process. The process in this case is the host, so no matter how many instances of VSTi's you add in your host the theoretical maximum is 2GB (or 3GB of course).
Q2: The short answer is...no. There are several hindering things:
1. 32-bit XP only recognizes 4GB to start with.
2. GigaStudio which is the exception here is a kernel-mode app and will suffer heavily from the 3GB switch as it will be on the losing side of the memory split.
3. With GS3 you're so far able to get a maximum of 1.1GB per machine whatever you do. The new VST implementation of GigaStudio, GVI, will change all this though as it will run completely in user-mode just like everything else and will thus benefit from the /3GB tweak.
Go with whatever you feel comfortable with is my motto. Personally being a zero as far as Macs go I'd get myself a PC with 64-bit hardware which will be possible to upgrade to 64-bit XP when the apps and not the least drivers are ready for it.
/Mattias
Thank you Mattias - good advice - cleared up a few issues.....
So I am hearing that a combination of a 64XP and GVI would be pretty amazing as far as RAM access and future compatibilty is concerned - actually WHATEVER app I choose (Bidule Plogue / VStack etc etc) I am getting an uplift in RAM access due to 64bit XP seeing more physical RAM - correct?
thank you....PaulM