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Xeon is a generation of Intel processors designed specifically for servers and workstations

. The different versions differ in their 32-bit processor architectures and have changed enormously in their performance values since their introduction in 1998. The first Xeon (P6) from 1998 was a 32-bit processor that was a variant of the Pentium processors and had the same processor core as these. Technologically Xeon are manufactured with most different technologies, so the first with a structure width of

250 nm and 180 nm (Xeon P6), the following (Xeon NetBurst) from 2001 already in 180 nm and 65 nm, the following development leap to the Xeon (Core) was manufactured in 65 nm and 45 nm, as well as the Xeon (Nehalem)

The development of the clock frequencies

Development stages of Intel's Xeon

Development stages of Intel's Xeon

An equally dynamic development took place withthe clock frequencies of the processors and the front site buses


Processor clock speeds increased from 400 MHz to 1.0 GHz (P6) to 1.4 GHz to 3.66 GHz (NetBurst), the clock speed for the front side bus (FSB) increased from 100 MHz to 400 MHz (Core) and with Intel's Quick Path Interconnect (QPI) even up to 6.4 GT/s (Giga transfers per second). Xeons are available for the CPU socketsSlot 2, Socket

495, 603, 604 and 771.Xeons have different Level 2 caches with memory capacities between 256 KB and 2 MB, and L3 caches up to 16 MB. It is suitable for multiprocessor systems

with two, four or eight processors working in parallel

The extended Xeon concept

Xeon dual-core processor in 65 nm technology, photo: Intel

Xeon dual-core processor in 65 nm technology, photo: Intel

The Xeon has been extended by an Opteron-compatible 64-bit variant, the EMT64. This Intel Extended Memory Technology (EMT) concept has a wide address bus that supports an addressable memory range of several terabytes (TB) and can scale the main memories available in practice with many gigabytes (GB). The main memory is not managed directly by the central processing unit

, but by a central memory controller hub (MCH). All processors in the system communicate with the EMT64 via the common front side bus (FSB), albeit at 800 MHz. In addition, the Xeon-64 offers hyperthreading, which makes the processor core look like a dual-core processor

to theoutside world. The Xeon is available as a dual-core and quad-core

processor andalso with eight processor cores, and also in many variants with clock speeds between 3.2 GHz and 3.6 GHz.

The EMT64 has a shared bus architecture based on the Pentium 's x86 architecture and an extended SSE instruction set, StreamingSIMD

. During its development, the Xeon had a variety of codenames, including Drake, Cascades, Foster, Prestonia, Nocona, Irwindale, Paxville, Tusla, Woodcrest, Bloomfield, Gainestown and many more.

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Englisch: Xeon
Updated at: 18.04.2012
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