The
Pentium M brand refers to a family of mobile single-core x86
microprocessorA microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
s (with the modified Intel
P6 microarchitectureThe P6 microarchitecture is the sixth generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is sometimes referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M...
) introduced in March 2003 (during the heyday of the
Pentium 4Pentium 4 was a line of single-core desktop and laptop central processing units , introduced by Intel on November 20, 2000 and shipped through August 8, 2008. They had a 7th-generation x86 microarchitecture, called NetBurst, which was the company's first all-new design since the introduction of the...
desktop CPUs), and forming a part of the Intel
Carmel notebook platform under the then new
CentrinoThe Centrino brand represents Intel Wi-Fi and WiMAX adapters. It was formerly a platform-marketing initiative from Intel until January 7, 2010....
brand. The
Pentium M processors had a maximum
thermal design powerThe thermal design power , sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate. For example, a laptop's CPU cooling system may be designed for a 20 watt TDP, which means that it can dissipate up to 20 watts of heat...
(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 IIIThe Pentium III brand refers to Intel's 32-bit x86 desktop and mobile microprocessors based on the sixth-generation P6 microarchitecture introduced on February 26, 1999. The brand's initial processors were very similar to the earlier Pentium II-branded microprocessors...
–branded CPU by adding the front-side bus (FSB) interface of Pentium 4, an improved instruction decoding and issuing front end, improved branch prediction,
SSE2SSE2, Streaming SIMD Extensions 2, is one of the Intel SIMD processor supplementary instruction sets first introduced by Intel with the initial version of the Pentium 4 in 2001. It extends the earlier SSE instruction set, and is intended to fully supplant MMX. Intel extended SSE2 to create SSE3...
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
CoreYonah was the code name for Intel's first generation of 65 nm process mobile microprocessors, based on the Banias/Dothan-core Pentium M microarchitecture. SIMD performance has been improved through the addition of SSE3 instructions and improvements to SSE and SSE2 implementations, while integer...
-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 4Pentium 4 was a line of single-core desktop and laptop central processing units , introduced by Intel on November 20, 2000 and shipped through August 8, 2008. They had a 7th-generation x86 microarchitecture, called NetBurst, which was the company's first all-new design since the introduction of the...
, but instead a heavily modified version of the
Pentium IIIThe Pentium III brand refers to Intel's 32-bit x86 desktop and mobile microprocessors based on the sixth-generation P6 microarchitecture introduced on February 26, 1999. The brand's initial processors were very similar to the earlier Pentium II-branded microprocessors...
Tualatin design (itself based on the
Pentium ProThe Pentium Pro is a sixth-generation x86 microprocessor developed and manufactured by Intel introduced in November 1, 1995 . It introduced the P6 microarchitecture and was originally intended to replace the original Pentium in a full range of applications...
core design). It is optimised 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 4Pentium 4 was a line of single-core desktop and laptop central processing units , introduced by Intel on November 20, 2000 and shipped through August 8, 2008. They had a 7th-generation x86 microarchitecture, called NetBurst, which was the company's first all-new design since the introduction of the...
(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. The Pentium M 740 has been tested to perform up to approximately 7,400 MIPS and 3.9 GFLOPS (using SSE2).
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,
SSE2SSE2, Streaming SIMD Extensions 2, is one of the Intel SIMD processor supplementary instruction sets first introduced by Intel with the initial version of the Pentium 4 in 2001. It extends the earlier SSE instruction set, and is intended to fully supplant MMX. Intel extended SSE2 to create SSE3...
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
SpeedStepSpeedStep is a trademark for a series of dynamic frequency scaling technologies built into some Intel microprocessors that allow the clock speed of the processor to be dynamically changed by software...
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 200 MHz, 400 MHz, 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
AOpenAOpen is a major electronics manufacturer from Taiwan that makes computers and parts for computers. AOpen used to be the Open System Business Unit of Acer Computer Inc. which designed, manufactured and sold computer components. It incorporated in December 1996 as a subsidiary of Acer Group with an...
,
DFIDFI, or Diamond Flower Inc., is a major motherboard manufacturer based in Taiwan.-History:DFI was first established in 1981 by Y.C Lu. At that time, DFI began as a graphics card maker with a turnover of 100 cards...
and
MSIMicro-Star International Co., Ltd is a Taiwan-based electronics company and one of the world's largest motherboard and video card manufacturers.-Overview:MSI is one of the top three motherboard and video card manufacturers worldwide...
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
ASUSASUSTeK Computer Incorporated is a multinational computer technology and consumer electronics product manufacturer headquartered in Taipei, Taiwan. Its product range includes motherboards, desktops, laptops, monitors, tablet PCs, servers and mobile phones...
to allow the use of Pentium M processors in selected ASUS motherboards designed for
Socket 478Socket 478 is a 478-contact CPU socket used for Intel's Pentium 4 and Celeron series CPUs.Socket 478 was launched with the Northwood core to compete with AMD's 462-pin Socket A and their Athlon XP processors. Socket 478 was intended to be the replacement for Socket 423, a Willamette-based...
Pentium 4Pentium 4 was a line of single-core desktop and laptop central processing units , introduced by Intel on November 20, 2000 and shipped through August 8, 2008. They had a 7th-generation x86 microarchitecture, called NetBurst, which was the company's first all-new design since the introduction of the...
processors.
Shuttle Inc.Shuttle is a Taiwan-based manufacturer of motherboards, barebone computers, complete PC systems, and monitors. Throughout the last 10 years, Shuttle has been one of the world's top 10 motherboard manufacturers, and gained fame in 2001 with the introduction of the Shuttle SV24, one of the world's...
offers packaged Pentium M desktops, marketed for low energy consumption and minimal cooling system noise. Pentium M processors are also of interest to
embedded systemAn embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s' manufacturers because the low power consumption of the Pentium M allows the design of fanless and miniaturized embedded PCs.
Banias
As the M line was originally designed in
IsraelThe State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, the first Pentium M was identified by the codename
BaniasBanias is an archaeological site by the ancient city of Caesarea Philippi, located at the foot of Mount Hermon in the Golan Heights...
, named after an ancient site in the
Golan Heights. The Intel Haifa Israel team had previously been working on the memory controller for
TimnaTimna was the codename of a proposed central processing unit family by Intel. The project was announced in 1999 and was designed in Haifa, Israel; "Timna" is also the name of a valley in Israel....
, 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
FSBA front-side bus is a computer communication interface often used in computers during the 1990s and 2000s.It typically carries data between the central processing unit and a memory controller hub, known as the northbridge....
, and had 1 megabyte (MB) of Level 2 cache. The core average
TDPThe thermal design power , sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate. For example, a laptop's CPU cooling system may be designed for a 20 watt TDP, which means that it can dissipate up to 20 watts of heat...
(Thermal Design Power) is 24.5 watts.
The
CPUIDThe CPUID opcode is a processor supplementary instruction for the x86 architecture. It was introduced by Intel in 1993 when it introduced the Pentium and SL-Enhanced 486 processors....
signature for a Banias is 0x69X.
Dothan
Intel launched its improved Pentium M, formerly known as
Dothan, named after another
ancient townDothan was a city located at north of Shechem, and about 100 km north of Hebron. Eusebius places it 12 miles to the north of Sebaste...
in Israel, on May 10, 2004. Dothan Pentium M processors (product code 80536,
CPUIDThe CPUID opcode is a processor supplementary instruction for the x86 architecture. It was introduced by Intel in 1993 when it introduced the Pentium and SL-Enhanced 486 processors....
0x6DX) are among the first Intel processors to be identified using a "processor number" rather than a clockspeed rating, and the mainstream versions are known as Pentium M 710 (1.4 GHz), 715 (1.5 GHz), 725 (1.6 GHz), 735 (1.7 GHz), 740 (1.73 GHz), 745 (1.8 GHz), 750 (1.86 GHz), 755 (2.0 GHz), and 765 (2.1 GHz).
These 700 series Pentium M processors retain the same basic design as the original Pentium M, but are manufactured on a
90 nmThe 90 nm process refers to the level of CMOS process technology that was reached in the 2002–2003 timeframe, by most leading semiconductor companies, like Intel, AMD, Infineon, Texas Instruments, IBM, and TSMC....
process, with twice the secondary cache. Die size, at 84 mm
2, remains in the same neighborhood as the original Pentium M, even though the 700 series contains approximately 140 million transistors, most of which make up the 2 MB cache.
TDPThe thermal design power , sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate. For example, a laptop's CPU cooling system may be designed for a 20 watt TDP, which means that it can dissipate up to 20 watts of heat...
is also down to 21 watts (from 24.5 watts in Banias), though power use at lower clockspeeds has increased slightly.
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 bitThe NX bit, which stands for No eXecute, is a technology used in CPUs to segregate areas of memory for use by either storage of processor instructions or for storage of data, a feature normally only found in Harvard architecture processors...
) (and
PAEIn computing, Physical Address Extension is a feature to allow x86 processors to access a physical address space larger than 4 gigabytes....
support required for it was enabled, unlike earlier Pentium Ms that had it disabled). These processors include the 730 (1.6 GHz), 740 (1.73 GHz), 750 (1.86 GHz), 760 (2.0 GHz) and 770 (2.13 GHz). These models all 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 has models running at clock speeds from 1.0 GHz to 2.26 GHz as of July 2005. The models with lower frequencies were either low voltage or ultra-low voltage CPUs designed for even better 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.
Core Solo and Core Duo
The next generation of processors (with a microarchitecture being a derivative of
P6The P6 microarchitecture is the sixth generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is sometimes referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M...
found in Pentium M CPUs), codenamed
Yonah, was released under the
Intel CoreYonah was the code name for Intel's first generation of 65 nm process mobile microprocessors, based on the Banias/Dothan-core Pentium M microarchitecture. SIMD performance has been improved through the addition of SSE3 instructions and improvements to SSE and SSE2 implementations, while integer...
brand, as Core Duo and Core Solo.
See also
- P6 (microarchitecture)
The P6 microarchitecture is the sixth generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is sometimes referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M...
- Centrino
The Centrino brand represents Intel Wi-Fi and WiMAX adapters. It was formerly a platform-marketing initiative from Intel until January 7, 2010....
- List of Intel Pentium M microprocessors
External links