Prescott 2M (Extreme Edition)

Prescott 2M (Extreme Edition)

Intel, by the first quarter of 2005, released a new Prescott core with 6x0 numbering, codenamed "Prescott 2M". Prescott 2M is also sometimes known by the name of its Xeon derivative, "Irwindale". It features Intel 64, the XD Bit, EIST (Enhanced Intel SpeedStep Technology), Tm2 (for processors at 3.6GHz and above), and 2 MB of L2 cache. However, any advantage introduced by the added cache is mostly negated due to higher cache latency, and the double word size if using Intel 64 mode. Rather than being a targeted speed boost the double size cache is intended to provide the same space and hence performance for 64-bit mode operations.

6xx series Prescott 2Ms have incorporated Hyper-Threading in order to speed up some processes that use multithreaded software, such as video editing.

On 14 November 2005, Intel released Prescott 2M processors with VT (Virtualization Technology, codenamed "Vanderpool") enabled. Intel only released two models of this Prescott 2M category: 662 and 672, running at 3.6 and 3.8 GHz, respectively.

Cedar Mill

The final revision of the Pentium 4 was Cedar Mill, released in early 2006. This was simply a straight shrink of the 600-series core to 65 nm, with no real feature additions. Cedar Mill had a lower heat output than Prescott, with a TDP of 86 W. The Core Stepping of D0 in late 2006 reduced this to 65 watts. It has a 65 nm core and features a 31-stage pipeline (just like Prescott), 800 MT/s FSB, Intel 64, Hyper-Threading and Virtualization Technology. As with Prescott 2M, Cedar Mill also has 2 MB of L2 cache. It was released as Pentium 6x1 and 6x3 (product code 80552) at frequencies from 3.0 GHz up to 3.6 GHz. Overclockers managed to exceed 8 GHz with these processors. None of the 6x1 range (631, 641, 651, and 661) has Virtualization Technology support. As of March 2007 it has not been possible to obtain 6x3 nor have Intel any records of this product line on their homepage.

To distinguish Cedar Mill CPUs from Prescott CPUs with the same features, Intel added 1 to their model numbers. Thus, Pentium 4 631, 641, 651 and 661 are 0.065 micron microprocessors, while Pentium 630, 640, 650 and 660 respectively are their 0.09 micron equivalents.