The two server types are aimed at very different needs:
- Multiprocessor Windows servers, which have also been referred to as Intel mainframes, serve as traditional back-end systems
- Blades allow for high-density edge-of-network tasks such as Web server farms.
In multiprocessor systems up to 64 processors are contained in the same housing. Blades normally only carry two processors but they are usually housed in a chassis that takes six or more blades. These boxes can be stacked in a rack to offer more processors in the same space as the multiprocessor servers.
In theory, blades could offer greater raw processing power with clustering but they cannot deliver the same degree of memory sharing flexibility as the multiprocessor servers.
Dell is following its usual low-pricing policy to provide its first blade server, the Poweredge 1655MC. This is a three-unit high housing that can contain up to six dual Intel Pentium III processor blades.
The company has cut costs by including shared redundant management cards, power supplies, cooling fans and network switches. Dell claims this makes the unit price 30% less than competing blade servers that have redundant modules for each blade.
Open Manage Remote Install software is provided to support remote installation of software across numerous blades simultaneously. There is also software to manage the server blades and monitor performance.
The blade servers, supplied with Microsoft Windows 2000 or Red Hat Linux, start at $3,298 (£2,124) for an enclosure and a single blade.
IBM's eServer Bladecentre T71 was announced in September and is now shipping. The seven-unit enclosure can hold up to 14 dual Intel Xeon processor blades or 84 blades per rack.
Each Bladecentre contains up to four load-balancing power supplies and four hot-swap switch modules supporting Gigabit Ethernet and Fibre Channel for connecting to Sans. The servers run Linux, Windows or Novell Netware with prices starting at £4,089 for an enclosure and single blade.
NEC's latest multiprocessor server takes it into the 16-way market. The Express 5800/1000 was first launched in Japan as a Linux server and called the TX7, but will be relaunched to coincide with Microsoft's release of Windows .net Server 2003 next April.
The server is based on Intel Itanium 2 processors and takes advantage of the new Windows' ability to run on non-uniform memory access systems. The servers are expected to cost $365,000 for an eight-processor system with 8Gbytes memory.
HP is also expected to enter the Windows market at about the same time with a 64-processor version of its Superdome server but prices will not be announced until nearer the release date.
At Comdex Fall, Bill Gates, Microsoft's chief architect, started to talk up the high-end multiprocessor market.
This marks a change from Microsoft's championing of distributed server architectures over the last 10 years and marks the increasing momentum to replace Unix and mainframe systems with Windows running on Intel.