This might sound like a silly question, but will Exchange 2003 perform better on a quad core processor than it would on dual or single core processors, all other things being equal? Thanks Paul.

On the Exchange Blog Site, there is this entry which is something good to read if you are talking about Exchange Hardware. http://msexchangeteam.com/archive/2007/01/16/432222.aspx UPDATE 2: Exchange 2007 Processor and Memory Recommendations In the comments, a Microsoft Blogger makes this comment: Exchange 2007 has been developed and tested to use the core counts listed in the posting (based on server roles). Quad core processors do not change this guidance by themselves. Exhcange 2007 will work great on quad core processors. What depends is the number of sockets your server has. Right now, quad core processors are only available for single and dual socket servers. That means the max core count is 8 for Exchange 2007 which we will be happy to utilize. When 4 socket servers are available with quad core processors; then you begin to exceed the max number of processor cores Exchange 2007 will effectively utilize. 8 processor cores is currently our recommended maximum and this will most likely not change with the advent of 4 socket, quad core server (16 cores). When these 16 core servers are availble, they may not be a good choice for dedicated Exchange 2007 server roles (4 socket dual core or 2 socket quad core may be a better fit). As this blog says, we recommend 8 cores max.

That's great for 2007, but what about Exchange 2003 (SP2) ?

Sorry about that.... This article talks about duel core being really good, and the fact that Exchange can support up to 8 processors. I haven't seen anything new from Microsoft about EX 2003 and quad core. But.. I can tell youa branch office of ourshas a duel proc quad core server that is running Exchange 2003 just fine. It replaced an older 4 proc hyperthreaded system. http://support.microsoft.com/kb/827281/en-us