Семейство мобильных процессоров Intel Pentium M

Family of Intel microprocessors

The Pentium M is a family of mobile 32 bit single core x86 microprocessors (with the modified Intel P6 microarchitecture) introduced in March 2003 and forming a part of the Intel Carmel notebook platform under the then new Centrino brand. The Pentium M processors had a maximum thermal design power (TDP) of 5–27 W depending on the model, and were intended for use in laptops (thus the "M" suffix standing for mobile). They evolved from the core of the last Pentium III–branded CPU by adding the front side bus (FSB) interface of Pentium 4, an improved instruction decoding and issuing front end, improved branch prediction, SSE2 support, and a much larger cache. The first Pentium M–branded CPU, code named Banias, was followed by Dothan. The Pentium M line was removed from the official price lists in July 2009, when the Pentium M branded processors were succeeded by the Core branded dual core mobile Yonah CPU with a modified microarchitecture. It replaced the Pentium 4 M processor, which suffered from power consumption and heat problems.

As the M line was originally designed in Israel, the first Pentium M was identified by the codename Banias, named after an ancient site in the Golan Heights. The Intel Haifa team had previously been working on the memory controller for Timna, which was based on earlier P6 memory controller designs giving them detailed knowledge of P6 architecture which they used when Intel gave them a crash project to create a backup mobile CPU. Given the product code 80535, it initially had no model number suffix, but was later identified as the Pentium M 705. It was manufactured on a 130 nm process, was released at frequencies from 900 MHz to 1.7 GHz using a 400 MT/s FSB, and had 1 megabyte (MB) of Level 2 cache. The core average TDP (Thermal Design Power) is 24.5 watts. The Banias family processors internally support Physical Address Extension (PAE) but do not show the PAE support flag in their CPUID information; this causes some operating systems (primarily Linux distributions) to refuse to boot on such processors since PAE support is required in their kernels. Using the 'forcepae' Linux boot option will allow Linux to boot using PAE in these cases. Windows 8 and later also refuses to boot on these processors for the same reason, as they specifically require PAE support to run properly. Attempting to boot with these processors installed (as well as on Dothan family processors without PAE support flag enabled in their CPUID info) will result in a crash when attempting to load ntoskrnl. exe early on in the boot process, with error code 0xc0000260 (UNSUPPORTED PROCESSOR).

On September 17, 2003, Intel unveiled plans for releasing its then next generation of Pentium M processors, codenamed "Dothan" by them. It was named after another ancient town in Israel, and it launched formally on May 10, 2004. Dothan Pentium M processors (product code 80536, CPUID 0x6DX) are among the first Intel processors to be identified using a "processor number" rather than a clockspeed rating; this allowed for more precise distinctions between different kinds of processors. The initial Dothan versions with the 400MT/s Front Side Bus (FSB) are known as Pentium M 710 (1.4 GHz), 715 (1.5 GHz), 725 (1.6 GHz), 735 (1.7 GHz), 745 (1.8 GHz), 755 (2.0 GHz), and 765 (2.1 GHz). These initial Dothan models all have a TDP of 21 W and a 2 MB L2 cache. These 700 series Dothan Pentium M processors retain the same basic design as the original Banias Pentium M, but are manufactured on a 90 nm process, with twice the secondary cache. Die size, at 87 mm2, remains in the same neighborhood as the original Pentium M, even though the 1000 series contains approximately 140 million transistors, most of which make up the 2 MB cache. TDP is also down to 21 watts with the 400 MT/s FSB (from 24.5 watts in Banias), though power use at lower clockspeeds has increased highly. However, tests conducted by third party hardware review sites show that Banias and Dothan equipped notebooks have roughly equivalent battery life. Additionally third party hardware review sites have benchmarked the Dothan at approx 10 20% better performance than the Banias in most situations. Revisions of the Dothan core were released in the first quarter of 2005 with the Sonoma chipsets and supported a 533 MT/s FSB and XD (Intel's name for the NX bit); and the PAE support flag in the CPUID was enabled, unlike earlier Pentium Ms that showed PAE unavailable. This resolved boot errors in Linux distributions as well as in Windows 8 and later. These revised Dothan processors include the 730 (1.6 GHz), 740 (1.73 GHz), 750 (1.86 GHz), 760 (2.0 GHz), 770 (2.13 GHz) and 780 (2.26 GHz) and have a TDP of 27 W and a 2 MB L2 cache. In July 2005, Intel released the 780 (2.26 GHz) and the low voltage 778 (1.60 GHz). The processor line had models running at clock speeds from 1.0 GHz to 2.26 GHz as of 2005. The models with lower frequencies were either low voltage or ultra low voltage CPUs designed for improved battery life and reduced heat output. The 718 (1.3 GHz), 738 (1.4 GHz), and 758 (1.5 GHz) models are low voltage (1.116 V) with a TDP of 10 W, while the 723 (1.0 GHz), 733 (1.1 GHz), and 753 (1.2 GHz) models are ultra low voltage (0.940 V) with a TDP of 5 W.

An ultra low power microprocessor based on the Dothan built on a 90 nm process with 512 KB L2 cache and 400 MT/s front side bus (FSB).

The next generation of processors, codenamed Yonah, were based on the Enhanced Pentium M architecture, and released under the Intel Core brand, as Core Duo and Core Solo.