Intel Xeon UP/DP (Conroe) processors
Introduction: October 2006
The Xeon brand refers to many families of Intel's x86 multiprocessing CPUs - for dual-processor (DP) and multi-processor (MP) configuration on a single motherboard targeted at non-consumer markets of server and workstation computers, and also at blade servers and embedded systems. The Xeon brand has been maintained over several generations of x86 and x86-64 processors. Older models added the Xeon moniker to the end of the name of their corresponding desktop processor, but more recent models used the name Xeon on its own. The Xeon CPUs generally have more cache than their desktop counterparts in addition to multiprocessing capabilities. Intel's (non-x86) IA-64 processors are called Itanium, not Xeon.
The Conroe core
The 3000 series, codenamed Conroe (product code 80557) dual-core Xeon (branded) CPU, released at the end of September 2006, was just rebranded version of the Intel's mainstream Conroe otherwise branded as Core 2 Duo (for consumer desktops). Unlike most Xeon processors, they only supported single-CPU operation. They used Socket T (LGA775), operated on a 1066MHz front-side bus, supported Enhanced Intel Speedstep Technology and Intel Virtualization Technology but did not support Hyper-Threading. Intel Processors with a number ending in "5" had a 1333MT/s FSB.
Source: Wikipedia, the free encyclopedia.