http://www.exchangeexchange.com/blogs/joel.stidley/archive/2005/11/16/278.aspx
Bob Muglia mentioned this in his Keynote Address on November 15, 2005 at the Microsoft IT Forum in Barcelona, Spain
a. Exchange 12
We are also focusing on the next version of Exchange next year, codenamed Exchange 12. That will also be 64-bit only. The reason we have chosen to do this with Exchange is because like database, messaging is an environment that can take advantage of all of the memory that 64-bit opens up. We found that Exchange 12 has tremendously different performance characteristics than Exchange 2003 because of the incremental memory that is available to 64-bit. We found that there is a 70% reduction in the IOs required for Exchange 12. That makes us a different beast in terms of the performance characteristics. Today’s Exchange systems typically require the highest performance SAN‑based systems to provide the scalability that major organisations need. With Exchange 12 and the incremental memory, the IO throughput is dramatically reduced. You may choose to continue to run it on a SAN, but the kind of IO subsystems and throughput needed will be reduced dramatically with Exchange 12. As we move forward, based on Exchange 12, our new generation solutions such as Small Business Server and Central will also be 64-bit only. We are planning on shipping those in the 2007 timeframe.
What do you think of this revelation? Good/Bad
Sources:
http://www.microsoft.com/emea/presscentre/presscentresite/itforum/pressMaterials.mspx
http://download.microsoft.com/download/9/b/3/9b3b38df-0a36-43ad-adab-6a9d5c0b8882/141878%20Microsoft%20Keynote%20Address%2015-11-05.doc
- Joel
After the release of the news a lot of speculation has been flying. Bink picks apart some of the critics here:
http://bink.nu/Article5422.bink
Take a look at Rodney's article on MSExchange.org for more details
Why 64-Bit is Good for E12
by Rodney Buike on MSExchange.org
Read the story at the source
http://www.msexchange.org/tutorials/Why-64-Bit-Good-E12.html
You may have already heard Microsoft’s recent announcement that the next version of Exchange, currently dubbed E12, will ship as a 64-bit application only to run on x64 CPUs. This may have left you wondering what x64 is, how 64-bit technology is going to benefit Exchange, or what you should be looking for when purchasing hardware now, so when E12 ships you are ready.