computers. As a response, Intel developed Smithfield, the first x86 dual-core processor intended for desktop computers, beating AMD's Athlon 64 X2 by a few weeks. Intel first launched Smithfield on April 16, 2005 in the form of the 3.2 GHz Hyper-threading enabled Pentium Extreme Edition 840. On May 26, 2005, Intel launched the mainstream Pentium D branded processor lineup with initial clock speeds of 2.8, 3.0, and 3.2 GHz with model numbers of 820, 830, and 840 respectively. In March 2006, Intel launched the last Smithfield processor, the entry-level Pentium D 805, clocked at 2.66 GHz with a 533 MT/s bus. The relatively cheap 805 was found to be highly overclockable; 3.5 GHz was often possible with good air cooling. Running it at over 4 GHz was possible with water cooling, and at this speed the 805 outperformed the top-of-the-line processors (May 2006) from both major CPU manufacturers (the AMD Athlon 64 FX-60 and Intel Pentium Extreme Edition 965) in many benchmarks including power consumption. The 805 and 820 models had a 95 watt TDP. All other models were rated at 130 watt. All Smithfield processors were made of two 90 nm Prescott cores, next to each other on a single die with 1 MB of Level 2 (L2) cache per core. Hyper-threading was disabled in all Pentium D 8xx-series Smithfields with the exception of the Pentium Extreme Edition 840. Smithfield did not support Intel VT-x—Intel's x86 virtualization (formerly Vanderpool). All Pentium D processors supported Intel 64 (formerly EM64T), XD Bit, and were manufactured for the LGA 775 form factor. The only motherboards guaranteed to work with the Pentium D (and Extreme Edition) branded CPUs were those based on the 945-, 955-, 965- and 975-series Intel chipsets, as well as the nForce 4 SLI Intel Edition and ATI Radeon Xpress. The Pentium D 820 did not work with the nForce 4 SLI Intel Edition chipset due to some power design issues, though they were rectified in the X16 version. The 915- and 925-series chipsets did not work at all with the Smithfields, as they did not support more than one core (to prevent manufacturers making a cheap dual CPU motherboard capable of supporting Xeon CPU's, as had happened with the 875P chipset). The 865- and 875-series chipsets supported multiprocessing. Motherboards with them might be Pentium D compatible with an updated BIOS. A week after its launch, Intel officially denied a