Microsoft’s Dan Reger has announced that Microsoft will not be supporting the Itanium architecture after Windows Server 2008 R2, SQL Server 2008 R2, and Visual Studio 2010. Mainstream support for Itanium on Windows Server 2008 and Windows Server 2008 R2 will end on July 9, 2013.
I can see why Microsoft would want to do this, given the release of the Intel Xeon 7500 series, that lets you have 64 logical processors and 1TB of DDR3 RAM in a four socket server. There are several hardware vendors that have announced eight socket Xeon 7500 systems, so you will be able to go to 128 logical processors and 2TB of RAM. Remember, SQL Server 2008 R2 and Windows Server 2008 R2 will let you go beyond the old 64 logical processor limit.
The main argument I have heard for Itanium is that the bigger systems that have Itanium processors usually have very large numbers of PCI-E expansion slots, so that you can use lots of host bus adapters (HBAs) or RAID controller cards to have much more I/O throughput capacity. Thomas Grohser from BWIN.COM once described Itanium systems as “like a big truck” because of their heavy duty I/O capacity, while Xeon systems were like “fast sports cars”. Another argument for Itanium was that they had better reliability, availability and serviceability (RAS) features compared to previous Xeon models. Intel has been moving more RAS features into the newer Xeons, so that lessens the appeal of the Itanium somewhat.
I would argue that a far more economical hardware solution for many applications would be a two socket, Xeon 5600 system with 72GB or 144GB of RAM. This would give you 24 logical processors (with HT enabled). A system like this, connected to a decent I/O subsystem can support a very large SQL Server workload with excellent performance.
Screenshot of Task Manager in a 4-socket Xeon 7500 system. Notice this system only has 64GB of RAM.
Screenshot of Task Manager in a 2-socket Xeon 5550 system at NewsGator. I was able to replace four, four-socket, Xeon 7040 and 7140 systems with this box back in December 2009, with very good results.