I need to install Exchange 2007 on a new server that has 64GB of physical memory allocated. Having spoken to the hardware vendor I can get the server to work by simply removing some of the DIMMS, but it is, techncially, not supported and, based on their lab expirences, I will expect to see a 20% drop in performance. So the quesion is, does Microsoft support setting the maximum memory size in the advance boot options (Windows 2008 SP2 OS) with Exchange 2007 SP2?? I have (yet) to find anything online although I am still searching. Thank you

With Exchange 2003, you'd want to remove any memory above 4GB, but I'm not aware of any memory limit with Exchange 2007 if you're running the legal-for-production 64-bit version.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Cheers Ed, 32GB is the recommended Microsoft maximum for Exchange 2007; http://technet.microsoft.com/en-us/library/bb738124(v=exchg.80).aspx "Although the Mailbox server role will utilize memory greater than 32 GB, for the reasons outlined earlier, 32 GB is the maximum recommended memory configuration and is considered the point of diminishing returns in terms of both cost and performance" So I am left with three choices.... 1- Physical server configuration set to 32GB (which will work, but we can expect to see some performance degradation) 2 - Leave the memory at 64GB which will work, but is not really recommended by Microsoft and MAY cause some performance issues (obviously the cost is not an issue for us) 3 - Limit the memory that the Windows OS uses through the advanced boot options to 32GB. This is the final option that I want to understand in more detail. So, is it supported with Exchange and, does it simply work or are there other limitations / factors to consider? Currently I will probbaly go with option 2, but it would be good to know if option 3 is a simple, risk free alternative

You are misreading that. In Exchange 2003, installing more than 4GB would cause performance problems because of design flaws surrounding the 32-bit memory limitation. We MVPs routinely advised people to remove excess memory from Windows 2003 platforms running Exchange 2003. Windows 2007 is 64-bit so there is no such problem. The article is telling you that 32GB is the maximum recommended because when you go above that you don't get much for your money. But that isn't the question you asked, you asked whether there is a performance hit if you do, and nowhere in the article you cite does it say you will.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

hi, any update? thanks, CastinLu TechNet Community Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com