Xeon

Intel's current generation of server-class microprocessors for PCs. The first Xeon processor was released in 1998 as the Pentium II Xeon.

The Pentium II Xeon uses either a 440GX or 450NX chipset. In 2000, the Pentium II Xeon was replaced by the Pentium III Xeon.

In 2001, the Pentium III Xeon was replaced with the Intel Xeon processor. The Xeon is based on Intel's NetBurst architecture and is similar to the Pentium 4 CPU.

The latest addition to the Xeon family is the Xeon MP processor, released in 2002, which combined NetBurst with Intel's Hyper-Threading Technology. Its chipsets use socket 603 and has GC-LE versions for the low end (2 processors, 16Gb memory addressable) and GC-HE for the high end (4 processors or more, 64Gb addressable), all using a 400Mhz bus.

Like Intel's standard x86/IA-32 family of consumer desktop PC processors, the Xeon line of processors are 32-bit. A 64-bit version of the Xeon is planned and will compliment (or potentially replace) Intel's Itanium CPU.

On May 9, 2004, Intel announced that future Xeon processors would be based on the company's Pentium M architecture. Interestingly, the Pentium M is based strongly on Intel's Pentium III architecture, so "new" Xeon may actually be more similar to the Pentium III Xeon than the NetBurst-based Xeons.

See also: List of Intel microprocessors

Xeon Processors, Designations, and Characteristics
Public Desigination	Core (Intel Codename)	CPU Frequency	Frontside Bus Frequency / Theoretical Bandwidth	Cache	Additional Features
Pentium II Xeon	Drake	400MHz-450MHz	100 MHz / 800MB/s	16K L1 data + 16K L1 instruction; 512KB/1MB/2MB L2	N/A
Pentium III Xeon	Tanner	500MHz-550MHz	100 MHz / 800MB/s	16K L1 data + 16K L1 instruction; 512KB/1MB/2MB L2	Support of SSE instructions and Processor Serial Number
Pentium III Xeon	Cascades	600MHz-1000MHz	133 MHz / 1066MB/s	16K L1 data + 16K L1 instruction; 256KB L2	On-Die L2 Cache
Pentium III Xeon	Cascades 2MB	700MHz-900MHz	100 MHz / 800MB/s	16K L1 data + 16K L1 instruction; 2MB L2	Larger L2 cache, and support for more than 2-way configurations
Xeon	Foster	1400MHz-2000MHz	100 MHz / 3.2GB/s	8K L1 data + 12K L1 instruction; 256KB L2	Based on Pentium 4's Netburst core; supports SSE2 and removes Processor Serial Number
Xeon MP	Foster MP	1400MHz-1600MHz	100 MHz / 3.2GB/s	8K L1 data + 12K L1 instruction; 256KB L2; 512K/1MB L3	Adds L3 cache, and support for more than 2-way configurations
Xeon	Prestonia	1600MHz-2800MHz	100 MHz / 3.2GB/s	8K L1 data + 12K L1 instruction; 512KB L2	Supports Hyper-Threading
Xeon	Prestonia B	2000MHz-3060MHz	133 MHz / 4.2GB/s	8K L1 data + 12K L1 instruction; 512KB L2	Faster Front-Side Bus
Xeon	Gallatin	3060MHz-3200MHz	133 MHz / 4.2GB/s	8K L1 data + 12K L1 instruction; 512KB L2; 1MB L3	Adds 1MB of L3 cache
Xeon MP	Gallatin	1500MHz-3000MHz	100 MHz / 3.2GB/s	8K L1 data + 12K L1 instruction; 512KB L2; 1MB/2MB/4MB L3	Adds L3 cache, and support for more than 2-way configurations
Xeon	Nocona	2800MHz-3600MHz	200 MHz / 6.4GB/s	16K L1 data + 12K L1 instruction; 1MB L2	Larger L2 cache; support for SSE3, EM64T and the NX (No eXecute) bit.