I've never had the volumes you're talking about, but I ran a TSM
5.1.5 server on an 85Mhz SPARCStation 5 running Solaris 8 with 128MB
of RAM connected to an old 4mm tape library and an optical jukebox.
It was mostly an exercise in learning about TSM on Solaris -- but it
successfully backed up a couple desktop machines and some AIX servers
from my dev lab.  It wasn't fast, but it performed the job admirably.
The biggest limitation (aside from installing Solaris on an 85Mhz
machine) was network bandwidth.

Using a modern 43p (w/100baseT ethernet) with a bunch of RAM and some
nice fast disks will likely serve you well.

-JD.

has anyone deployed TSM from a B50 or a 43p 140 ?
I need to back up about 4 GB a night on a local network from 2 clients and
maintain a total tape pool of about 2.5 TB on about 100,000 objects or less.

thank you for any assistance or guidance.
Don Levinson