microkernel design question

Hi VSTa folks! I have a question.

How much does the fact that every driver in VSTa runs as a separate
process impact performance?

As example, on my NetBSD box, I have the following "drivers" running:
        IDE
        SCSI
        ATAPI
        VGA card
        WSCons (virtual consoles driver)
        NE2000 network card
        TCP/IP
        NFS
        BSD FFS filesystem
        MS-DOS FAT filesystem
        Linux EXT2 filesystem
        ISO 9660 filesystem
        SoundBlaster sound card
        Sun audio interface
        MIDI
        PS/2 mouse

This is pretty typical for a real-world machine. On a VSTa box, each
of these 16 drivers/subsystems would be a separate process, with the
scheduling, context-switching and vm overhead that that implies.
OTOH, because the design of VSTa is for most everything to be a
usermode process, I'm sure the overhead is much less than in a
monolithic OS like UNIX. The question is, how much less, and does it
ever become the performance bottleneck?

-- 
Mirian Crzig Lennox                                Systems Anarchist
              Invest in America -- buy a Congressman!