I read on 'Juggling Terminal Service Resources' that for a 4GB Win2k3 32-bit server, Windows tends to take up 2GB and leave around 2GB for users' processes. It says that a good rule of thumb is to allocate 64MB of RAM for each Terminal session. So, for a 2GB of RAM I can accommodate around 32 concurrent Terminal sessions.

I'm planning to upgrade to a 64-bit Windows Server 2008. Will this assumption still hold true? If we have 8GB of RAM, How much RAM will Win2K8 take for its own and how much for the user process?

Do you have any recommendation for a load test tool for TS? I ran across
CitraTest_VU from Tevron. would you recommend it?

'Juggling Terminal Service Resources'
"In the real world, servers with 4 GB of RAM have been known to accommodate up to 75 terminal service sessions. Part of the reason for this is because some sessions will consume more memory than others. If a session is sitting idle or running a low end application such as Notepad then that session isn’t going to use anywhere near 64 MB of memory. That frees memory up for additional sessions."