Groove Agent and CPU upgrades

[Barry Warsaw]

I just pulled down Steinberg's Groove Agent drum "machine" VSTi demo and
played with it on my Cubase SX system.  Seems very cool and I'm
considering picking it up.  I've been using Virtual Guitarist for a
while now and like it (despite the disappointment about the lack of
upgrade and the stealth VGee release :).  I'm wondering if anybody else
has spent time with the real thing and has any feedback positive or
negative.

Also, I'm in desperate need of a CPU upgrade.  My box is a single
550MHz, 1GB, G4 with several SCSI160 drives.  It's essentially a Digital
Audio with some customizations.  The CPU is killing me though -- it
often pegs during busy mix downs and I have to bump tracks, which kind
of defeats the purpose of a DAW, y'know? :)

I've been eyeing the price drops on chip upgrades and the price points
are getting attractive.  But I'm unsure exactly which way to go,
especially when my main app is Cubase SX.  I've been looking at the
Powerlogix chips as they seem to have a fairly good rep from what I can
tell.

Is it better to get a single 1.2GHz chip or shoot for say a dual 867 or
933?  Can SX take full advantage of the dual processors?  I'm not sure I
can spend the bucks for a dual 1.2 upgrade.

I'm also worried about heat output.  Already, my G4 bakes my room pretty
well after a few hours.  While I suppose the internal fans in the G4
will keep the box itself cool, I'm worried about my A/C bills :).

Any insight would be greatly appreciated.

-Barry