I am trying to provide information on OWA capacity to my boss.His question is: "Need to know how many personnel could be using Outlook Web Access concurrently with the existing architecture and hardware in place. Let me know how many customers could be on the system at 80% of capacity.I have seen information on "Determining the Scalability of Combined Client Access and Hub Transport Server Roles in Exchange 2007" http://technet.microsoft.com/en-us/library/dd901772.aspxbut I don't have a combined CAS and HUB.Our CAS servers are Server 2k3 SP2 Standard Edition with 4GM of ram, 1 Quad Core 1.60GHz Intel Xeon processor.Karl

This is the only other document I'm aware of that touches this topic:http://www.microsoft.com/downloads/details.aspx?FamilyID=239666A9-B13C-4AD8-AEDB-3ED4ECBB95C5&displaylang=enOtherwise there is system center capacity planner which uses known rules like the server ratios recommended for each server role. Mike Crowley A+, Network+, Security+, MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator

to get a REAL answer you should use something like loadgen on a test environment with all of your specific software loaded as well Mike Crowley A+, Network+, Security+, MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator

Thanks - i will look at that.Karl

I thought of doing a loadgen, but my test environment is a single core VM running 2 GB or ram, so my tests would be invalid.Thanks thoughKarl

I understand. Just pass that back up to management. If they want real results they have to buy real hardware...but read that HMC link I gave you. its got some pretty good facts. Mike Crowley A+, Network+, Security+, MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator