Im currently planning out our Exchange 2010 deployment and am looking at potential hardware to use however reading some of the technet articles about minimum and recommended specs and they seen quite high. Does anyone have any suggestions as to what hardware would be needed for around a 200 user combined CAS/HT/MBX role server with a reasonably average load of around 100 msgs/per day per user. Im not looking for exact specs but if anyone has any suggestions they are most welcome, 200 or so users is fairly small scale I imagine, but much RAM is really needed? I want to avoid a situation where I get a server that has loads of RAM (some of the technet articles seem to indicate I should use 16GB!), and then find out that for 200 users barely any of it is use. Also, if anyone has any links to articles that indicate what sort of network usage is generated by an OWA or Outlook Anywhere user I would be grateful as one task still to do is to look at whether moving to Exchange will add any extra network traffic due to all the fancy new bits in OWA.

The below could be useful tools: 1) HP Sizer for Microsoft Exchange Server 2010: http://h71019.www7.hp.com/ActiveAnswers/us/en/sizers/microsoft-exchange-server-2010.html 2) Exchange 2010 Advisor from Dell(Online): http://advisors.dell.com/advisorweb/Advisor.aspx?advisor=b6372fc5-7556-4340-8328-b8a88e2e64b2-001ebc;4&c=us&l=en&cs=g_5 3) Exchange 2010 Mailbox Server role calculator provided by the Exchange team: http://msexchangeteam.com/archive/2009/11/09/453117.aspx Elie B. MCITP: EMEA|EA|SA; MCTS: Microsoft Exchange Server 2010, Configuration; Blog: http://blog.elieb.info

Thanks Elie, Id seen the Mailbox calc but didnt find it all that useful for what Im after however both the Dell and HP links were useful (despite them both wanting me to buy massive DAS arrays!). Im still interested in hearing peoples real-world experiences so if anyone has deployed a similar (ie. combined role server), it would very awesome to hear what specs you used and for how many users :)

I too would be interested in any one's real-world experiences. I am looking at replacing my Exchange 2003 box with a 2010 box. It seems like I have an even smaller scale environment than Nick-C. I only have around 50 mailboxes on my current setup with an average mailbox size of around 500MB. I am looking at a combined role server as well (as this will be the only Exchange box in the organization).