Hi all. I have read posts on many forums and still can't quite figure this out. I want to have as many VIs running as my machine has capacity. On the Vienna site it states that in 64 bit mode the full memory can be utilized, but it doesn't mention about 32 bit mode. I am using Digital Performer on a Mac Pro, 8 core, 16 gigs ram, system drive plus three velociraptors, to run Play, Kontact, etc.
I saw the now famous video on the cinesamples site demonstrating a huge orchestral template using Bidule. That is what I am am after. It just seems that VEP is a bit more graceful in dealing with audio issues and already has a 64 bit version for when MOTU decides to go 64 bit.
You should go for Vienna Ensemble Pro. VEPro comes in both 32 and 64bit versions, and you can run both at the same time with 32bit or 64bit host.
Currently Kontakt is 64bit on a Mac, so you can run many instruments with Kontakt in VEPro 64bit. PLAY is 32bit so you have to run it in VEPro 32bit version (yes it works now), however the 32bit VEPro is also prone to the 4gig (Virtual Memory) limit, so make sure you don't go overboard with that.
I currently have 16gigs of RAM in my Quad Mac and I have no problem maxing out the memory. With an 8-core Mac you should easily run out of RAM if you load enough instruments.