Intel Pentium Extreme Edition (Presler XE) processors
Introduction: January 2006
The Pentium D brand refered to two series of dual-core 64-bit x86 processors with the NetBurst microarchitecture. Each CPU comprised two single-core dies (CPUs) - next to each other - in one multi-chip module package. The brand's first processor, codenamed Smithfield, was released by Intel on May 25, 2005. Nine months later, Intel introduced its successor, codenamed Presler, but without offering significant upgrades in design, still resulting in a relatively high power consumption. By 2005, the NetBurst processors reached the clock speed barrier at 4GHz due to a thermal (and power) limit exemplified by the Presler's 130W TDP (a high TDP required additional cooling that can be noisy or expensive). The future belonged to more efficient and slower clocked dual-core CPUs on a single die instead of two. The dual die Presler's last shipment date on August 8, 2008 marked the end of the Pentium D brand and also the NetBurst microarchitecture.
The dual-core CPU ran very well with multi-threaded applications (typical for transcoding audio and video, compressing, photo and video editing and rendering, ray-tracing). The single-threaded applications alone, including most games, did not benefit from the second core of dual-core CPU over equally clocked single-core CPU. Nevertheless, the dual-core CPU was useful to run both the client and server processes of a game without noticeable lag in either thread, as each instance could be running on a different core. Furthermore, multi-threaded games benefited from the dual-core CPUs.
The Presler XE core
The Pentium Extreme Edition based on the dual-core Pentium D branded Presler was introduced as the 955 model, at 3.46GHz, and used a 1066MT/s FSB compared to the 800MT/s in the non-Extreme edition. A second version, the 965 at 3.73GHz followed in March 2006. Many overclockers, however, had been able to overclock the core to 4.26GHz using air cooling simply by raising the unlocked CPU multiplier.
The Presler Extreme Edition would run only combined with the Intel 975X chipset (it could also work with the 955X chipset, though this combination was not supported by Intel). The i975X featured the ICH7R southbridge and supported all Socket T (LGA775) Pentium 4, Pentium D, and Pentium Extreme Edition branded processors.
Source: Wikipedia, the free encyclopedia.