How do I judge memory and processor needed per app and users?

[tiash]

I need to spec an HP servers for 600 users. I need to have a idea on how to plan the server size for these users and apps. like exchange , fax serv, backup exec, O/S, etc.
[processor, HD, memory per user per app.]

I also need to know how many servers I should destribute the load on. I understand nothing is exact but If I could find away of judging an estimate it would help.

I'm looking for a way of planning other installs as well?

 

[MCorrell]

Have you called HP for advise? Their sales team should be able to set you up with everything you'll need. They're quite excellent.

Also, check here:

http://netserver.hp.com/netserver/tools/provided-tools.asp

 

[tiash]

HP is no use in this situation. but I realized that all of the applications have system requirements and user requirements. I found all I needed looking at the manufacturers sites.

What kind of support have you recieved from HP because all they have ever offered to me is part #s?