I have installeed BES onto a SBS 2003 R2 15 BB users and 15 work stations all at under 5% cpu and disk usage dual core 2.2 ghz 4 gigs of ram
I followed Gary's BES install guide for SBS 2003 or Domain Controller
http://www.blackberryforums.com.au/f...bs-2003-a.html
Hope this helps
SkyPilot