List of Intel Xeon microprocessors - Wikipedia, the free encyclopedia On 11 November 2007 Intel presented Yorkfield-based Xeons – called Harpertown (product code 80574) – to the public.[9] This family consists of dual die quad-core CPUs manufactured on a 45 nm process and featuring 1066 MHz, 1333 MHz, 1600 MHz front-side buses, with TDP rated from 40 W to 150 W depending on the model. These processors fit in the LGA 771 package. All models feature Intel 64 (Intel's x86-64 implementation), the XD bit, and Virtualization Technology. All except the E5405 and L5408 also feature Demand Based Switching.[15][16] The supplementary character in front of the model-number represents the thermal rating: an L depicts a TDP of 40 W or 50 W, an E depicts 80 W whereas an X is 120 W TDP or above. The speed of 3.00 GHz comes as four models, two models with 80 W TDP two other models with 120 W TDP with 1333 MHz or 1600 MHz front-side bus respectively. The fastest Harpertown is the X5492 whose TDP of 150 W is higher than those of the Prescott-based Xeon DP but having twice as many cores. (The X5482 is also sold under the name "Core 2 Extreme QX9775" for use in the Intel SkullTrail system.) οι Ε με το μικρότερο TDP ήταν ακριβότεροι.