Pentium M

Pentium M
Pentiummn.png
ProducedFrom March 12, 2003 to August 8, 2008
Common manufacturer(s)
  • Intel
Max. CPU clock rate900 MHz to 2.26 GHz
FSB speeds400 MT/s to 533 MT/s
Min. feature size0.13µm to 90nm
Instruction setMMX, SSE, SSE2
MicroarchitectureP6 variant
Cores1
Core name(s)
  • Banias
  • Dothan
Socket(s)
PredecessorIntel Pentium III
SuccessorIntel Core

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-branded processors were succeeded by the Core-branded dual-core mobile Yonah CPU with a modified microarchitecture.

Overview

The Pentium M represented a new and radical departure for Intel, as it was not a low-power version of the desktop-oriented Pentium 4, but instead a heavily modified version of the Pentium III Tualatin design (itself based on the Pentium II core design, which in turn had been a heavily improved evolution of the Pentium Pro). It is optimized for power efficiency, a vital characteristic for extending notebook computer battery life. Running with very low average power consumption and much lower heat output than desktop processors, the Pentium M runs at a lower clock speed than the laptop version of the Pentium 4 (The Pentium 4-Mobile, or P4-M), but with similar performance - a 1.6 GHz Pentium M can typically attain or even surpass the performance of a 2.4 GHz Pentium 4-M.[1] The Pentium M 740 has been tested to perform up to approximately 7,400 MIPS and 3.9 GFLOPS (using SSE2).[2]

The Pentium M coupled the execution core of the Pentium III with a Pentium 4 compatible bus interface, an improved instruction decoding/issuing front end, improved branch prediction, SSE2 support, and a much larger cache. The usually power-hungry secondary cache uses an access method which only switches on the portion being accessed. The main intention behind the large cache was to keep a decent-sized portion of it still available to the processor even when most of the L2 cache was switched off, but its size led to a welcome improvement in performance.

Other power saving methods include dynamically variable clock frequency and core voltage, allowing the Pentium M to throttle clock speed when the system is idle in order to conserve energy, using the SpeedStep 3 technology (which has more sleep stages than previous versions of SpeedStep). With this technology, a 1.6 GHz Pentium M can effectively throttle to clock speeds of 600 MHz, 800 MHz, 1000 MHz, 1200 MHz, 1400 MHz and 1600 MHz; these intermediate clock states allow the CPU to better throttle clock speed to suit conditions. The power requirements of the Pentium M varies from 5 watts when idle to 27 watts at full load. This is useful to notebook manufacturers as it allows them to include the Pentium M into smaller notebooks.

Although Intel has marketed the Pentium M exclusively as a mobile product, motherboard manufacturers such as AOpen, DFI and MSI have been shipping Pentium M compatible boards designed for enthusiast, HTPC, workstation and server applications. An adapter, the CT-479, has also been developed by ASUS to allow the use of Pentium M processors in selected ASUS motherboards designed for Socket 478 Pentium 4 processors. Shuttle Inc. offers packaged Pentium M desktops, marketed for low energy consumption and minimal cooling system noise. Pentium M processors are also of interest to embedded systems' manufacturers because the low power consumption of the Pentium M allows the design of fanless and miniaturized embedded PCs.

Intel Pentium M processor family
2003-2005 Logo 2006-2008 Logo Laptop
Code-name Process Date released
Original Pentium M brand logo New Pentium M brand logo Banias
Dothan
(130 nm)
(90 nm)
Mar 2003
Jun 2004
List of Intel Pentium M microprocessors
Other Languages
العربية: بنتيوم M
català: Pentium M
čeština: Pentium M
español: Intel Pentium M
Esperanto: Pentium M
français: Pentium M
한국어: 펜티엄 M
Bahasa Indonesia: Pentium M
italiano: Pentium M
magyar: Pentium M
Nederlands: Pentium M
日本語: Pentium M
polski: Pentium M
português: Pentium M
русский: Pentium M
slovenčina: Pentium M
svenska: Pentium M
Türkçe: Pentium M
українська: Pentium M
中文: 奔腾M