After that small hiccup with running Evolution on 32bit Linux and the memory limitations, we are now live on 64bit SLED 11 and the difference in speed is striking. The per user memory requirements have grown, but it's a small price to pay (and memory is cheap!). The top screen below is 220 concurrent Evolution sessions. CPU is barely used at all. Disks are configured RAID 1 which has proven to be the best for Evolution (RAID 5 is much slower). When using the Groupwise backend, hitting Send/Receive the dialog only appears for a split second. The server is has 4 CPUs, quad core and I think we could easily get 500 concurrent users on here with no performance penalty. I'll have a few days of tuning and minor issues. Next on deck for me: getting gdm fixed to allow XDMCP connections again, and starting to work on that new monster server to run Firefox.