Thanks to the all of you who replied to my enigma !!
Better I tell you what kind of experiment I'm doing to test the power of my system/template:
To start, I wanna say I'm very lazy and just want all my instruments to be ready when I start recording, in order to just click the "record" button on each midi track and go...so I created an APOCALIPTIC metaframe, composed by 2 x 64bit VEPRO instances/vframes (126 outputs, 14 midi channels each) , each hosting several K502 instances for a total amount of about 26 Kontakt instances (each one hosting 16 instruments), plus about 30 spare V.I. synths..
...in overall single midi tracks terms, I loaded exactly 440 instrument lol (articulations, alternative models instruments, different brands of synths and so on...)
for what regards the Kontakt counterpart, all instruments are obviously purged, being this I'm doing just an "idea" of standard template I'm going to apply to each of my songs (then I just reload the samples I need, based on the song)...the important for me was having a starting point with all I need already provided, and then subtract/exclude what I won't use (also to test the power of the 2.93GHz dual hex mac pro, with 32 gigs of ram)
The test, performed hosting 2 x VEPRO RTAS plugins from the VEPRO 5.0.10638 64bit server in Pro Tools 9.0.3 with Complete Production Toolkit 2, consist in this:
I set both the VEPRO plugin instances to x2 buffers (default) and set the Pro Tools/RME FF800 buffer to 1024 sample (max), then I record some midi data which consist in my hand going up and down on the keyboard fastly, touching all notes of all available octaves, in order to trigger them all...then I copy this data to all of the 440 midi track, changing slightly the starting point, and press play on pro tools...
the midi data triggers all the instruments, creating an absurd but creative cacophony which sounds like a mad waterfall,that reveals if the system is able to keep up...
the result of this crazy test is that maxing out everything I can make (more or less) working without artifacts about 400 istruments of all the bloody total 440 ones ,with very high cpu usage that reaches peaks of 97%....
...the triggering of all these instruments eats my ram after a while, and looking at the activity monitor, I notice I get swap of about 10 megs and VM is about 153 Gb...
..but the fact is that I get cpu overloads already before to run out of ram, but was asking myself ( to win this test ) if adding a comic amount of ram (96 Gb OWC ram) would someway help to reduce the cpu usage ( its idle, for instance), and oc helping me to purge less samples in Kontakt (which is set to 16 core multiprocessing, condition necessary to make this work, at least for my setup)
But might be that the only solution is to reduce the template, but this would be a pity, cuz I'm very lazy, and day-by-day even lazier, so I hate to load new instruments outside the template.
I allow you to laugh on me and think I'm crazy, which probably is the truth, but I'm this way and cannot change hehe