Thanks to Tim Sullivan from the sbslist for finding this one, it is an announcement that Exchange 12 will be released as 64bit only.
Question 1: Why did Microsoft make the decision to offer Exchange 12 as a 64-bit only application?
Answer: Email truly is a â€œmission criticalâ€ application in most organizations today, and we heard from our customers that they were pushing the limits with their current messaging solutions. Demands being placed on messaging solutions continue to grow, and by nature 32-bit email server systems have memory limitations (4GB) which restrict their ability to cost effectively support these needs. Additionally, customers want to consolidate their servers to manage cost and complexity. 64-bit servers provide the system architecture required to meet both of these needs (accommodating new demands and consolidating servers).
Question 2: Isnâ€™t 64 bit only required for very high scale customers?
Answer: The 64 bit architecture enables Exchange 12 to use inexpensive memory to reduce very expensive disk usage. Today, approximately 80% of the capital cost required to run Exchange is for storage. Our testing shows 64 bit Exchange 12 requires 4x fewer random IOâ€™s per second than 32 bit Exchange 2003, which translate into large savings for all customers â€“ especially as mailbox sizes grow.
Question 3: Will customers who want to upgrade to Exchange 12 be required to purchase new hardware?
Answer: The majority of server hardware being sold today is x64-based and many businesses are already enjoying its advantages and will not need to purchase new hardware. If you look at the CPU market today, the majority of the 32 bit only processors are diminishing greatly and being replaced with x64 capable processors. If a customer has not already made the move to x64 systems they will need to purchase new hardware for those servers upon which they plan to install and run Exchange 12.
Above is courtesy of Harold Wong mentioning it at a news conference. This would be a good time to check out the Opteron and familiarize yourself with the AMD x64 architecture. Their chips are very competitive with Intel on price (read: cheaper) and generally perform better (read: oh my god, it smoked a Xeon). Everything is going 64bit, so get ready. I bought a bunch of Celeron D’s last week ($80 chip) and they were all 64bit enabled.
Update: Its not just Exchange 12 going 64bit by the way. Remember, once the components go 64bit, so does SBS. As a matter of fact, Microsoft has promised 64bit optimized versions of Exchange Server 12, Windows Compute Cluster Server 2003, the Longhorn Small Business Server, Microsoft’s midmarket server, code-named “Centro,” and Windows Longhorn Server R2 (the Windows Server release expected around 2009).
Look at all the details in their press release: