P6 (microarchitecture)

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P6
Intel@250nm@P6@Deschutes@Pentium II@flipchip PB 713539-001 DSCx1 polysilicon microscope stitched@5x (38025161182).jpg
Die shot of Deschutes core
General information
LaunchedNovember 1, 1995;28 years ago (November 1, 1995)
Performance
Max. CPU clock rate 150 [1]  MHz to 1.40 GHz
FSB speeds66 MHz to 133 MHz
Cache
L1 cache Pentium Pro: 16 KB (8 KB I cache + 8 KB D cache)
Pentium II/III: 32 KB (16 KB I cache + 16 KB D cache)
L2 cache128 KB to 512 KB
256 KB to 2048 KB (Xeon)
Architecture and classification
Microarchitecture P6
Instruction set x86-16, IA-32
Extensions
  • MMX (Pentium II/III)
    SSE (Pentium III)
Physical specifications
Transistors
Cores
  • 1
Socket(s)
Products, models, variants
Model(s)
  • Celeron Series
  • Pentium II Series
  • Pentium III Series
  • Pentium Pro Series
  • Pentium II Xeon Series
  • Pentium III Xeon Series
Variant(s)
  • Pentium M
  • Enhanced Pentium M
History
Predecessor(s) P5
Successor(s) NetBurst, Pentium M
Support status
Unsupported

The P6 microarchitecture is the sixth-generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is frequently referred to as i686. [2] It was planned to be succeeded by the NetBurst microarchitecture used by the Pentium 4 in 2000, but was revived for the Pentium M line of microprocessors. The successor to the Pentium M variant of the P6 microarchitecture is the Core microarchitecture which in turn is also derived from P6.

Contents

P6 was used within Intel's mainstream offerings from the Pentium Pro to Pentium III, and was widely known for low power consumption, excellent integer performance, and relatively high instructions per cycle (IPC).

Features

The P6 core was the sixth generation Intel microprocessor in the x86 line. The first implementation of the P6 core was the Pentium Pro CPU in 1995, the immediate successor to the original Pentium design (P5).

P6 processors dynamically translate IA-32 instructions into sequences of buffered RISC-like micro-operations, then analyze and reorder the micro-operations to detect parallelizable operations that may be issued to more than one execution unit at once. [3] The Pentium Pro was the first x86 microprocessor designed by Intel to use this technique, though the NexGen Nx586, introduced in 1994, did so earlier.

Other features first implemented in the x86 space in the P6 core include:

P6 based chips

P6 Variant Pentium M

P6 Pentium M
Pentium M.jpg
General information
LaunchedMarch 12, 2003
Performance
Max. CPU clock rate 600 MHz to 2.26 GHz
FSB speeds400 MT/s to 533 MT/s
Cache
L1 cache 64KB (32 KB I Cache + 32 KB D cache)
L2 cache512 KB to 2048 KB
Architecture and classification
Microarchitecture P6
Instruction set x86-16, IA-32
Extensions
Physical specifications
Transistors
Cores
  • 1
Socket(s)
Products, models, variants
Model(s)
  • A100 Series
  • EP80579 Series
  • Celeron M Series
  • Pentium M Series
History
Predecessor(s) NetBurst
Successor(s) Enhanced Pentium M
Support status
Unsupported

Upon release of the Pentium 4-M and Mobile Pentium 4, it was quickly realized that the new mobile NetBurst processors were not ideal for mobile computing. NetBurst-based processors were simply not as efficient per clock or per watt compared to their P6 predecessors. Mobile Pentium 4 processors ran much hotter than Pentium III-M processors without significant performance advantages. Its inefficiency affected not only the cooling system complexity, but also the all-important battery life. Intel went back to the drawing board for a design that would be optimally suited for this market segment. The result was a modernized P6 design called the Pentium M.

Design Overview [6]

The Pentium M was the most power efficient x86 processor for notebooks for several years, consuming a maximum of 27 watts at maximum load and 4-5 watts while idle. The processing efficiency gains brought about by its modernization allowed it to rival the Mobile Pentium 4 clocked over 1 GHz higher (the fastest-clocked Mobile Pentium 4 compared to the fastest-clocked Pentium M) and equipped with much more memory and bus bandwidth. [6]

The first Pentium M family processors ("Banias") internally support 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. [7] Windows 8 and later also refuses to boot on these processors for the same reason, as they specifically require PAE support to run properly. [8]

Banias/Dothan variant

P6 Variant Enhanced Pentium M

P6 Enhanced Pentium M
General information
Launched2006
Performance
Max. CPU clock rate 1.06 GHz to 2.33 GHz
FSB speeds533 MT/s to 667 MT/s
Cache
L1 cache 64 KB
L2 cache1 MB to 2 MB
2 MB (Xeon)
Architecture and classification
Microarchitecture P6
Instruction set x86-16, IA-32
Extensions
Physical specifications
Transistors
Cores
  • 1-2
Socket(s)
Products, models, variants
Model(s)
  • Celeron M Series
  • Pentium Dual-Core Series
  • Core Solo Series
  • Core Duo Series
  • Xeon LV Series
History
Predecessor(s) Pentium M
Successor(s) Intel Core
Support status
Unsupported

The Yonah CPU was launched in January 2006 under the Core brand. Single and dual-core mobile version were sold under the Core Solo, Core Duo, and Pentium Dual-Core brands, and a server version was released as Xeon LV. These processors provided partial solutions to some of the Pentium M's shortcomings by adding:

This resulted in the interim microarchitecture for low-voltage only CPUs, part way between P6 and the following Core microarchitecture.

Yonah variant

Successor

On July 27, 2006, the Core microarchitecture, a derivative of P6, was launched in form of the Core 2 processor. Subsequently, more processors were released with the Core microarchitecture under Core 2, Xeon, Pentium and Celeron brand names. The Core microarchitecture is Intel's final mainstream processor line to use FSB, with all later Intel processors based on Nehalem and later Intel microarchitectures featuring an integrated memory controller and a QPI or DMI bus for communication with the rest of the system. Improvements relative to the Intel Core processors were:

While all these chips are technically derivatives of the Pentium Pro, the architecture has gone through several radical changes since its inception. [9]

See also

Related Research Articles

<span class="mw-page-title-main">Athlon</span> Brand of microprocessors by AMD

Athlon is the brand name applied to a series of x86-compatible microprocessors designed and manufactured by AMD. The original Athlon was the first seventh-generation x86 processor and the first desktop processor to reach speeds of one gigahertz (GHz). It made its debut as AMD's high-end processor brand on June 23, 1999. Over the years AMD has used the Athlon name with the 64-bit Athlon 64 architecture, the Athlon II, and Accelerated Processing Unit (APU) chips targeting the Socket AM1 desktop SoC architecture, and Socket AM4 Zen microarchitecture. The modern Zen-based Athlon with a Radeon Graphics processor was introduced in 2019 as AMD's highest-performance entry-level processor.

<span class="mw-page-title-main">Celeron</span> Line of discontinued microprocessors made by Intel

Celeron is a discontinued series of low-end IA-32 and x86-64 computer microprocessor models targeted at low-cost personal computers, manufactured by Intel. The first Celeron-branded CPU was introduced on April 15, 1998, and was based on the Pentium II.

<span class="mw-page-title-main">Pentium 4</span> Brand by Intel

Pentium 4 is a series of single-core CPUs for desktops, laptops and entry-level servers manufactured by Intel. The processors were shipped from November 20, 2000 until August 8, 2008. It was removed from the official price lists starting in 2010, being replaced by Pentium Dual-Core.

<span class="mw-page-title-main">Pentium II</span> Intel microprocessor

The Pentium II brand refers to Intel's sixth-generation microarchitecture ("P6") and x86-compatible microprocessors introduced on May 7, 1997. Containing 7.5 million transistors, the Pentium II featured an improved version of the first P6-generation core of the Pentium Pro, which contained 5.5 million transistors. However, its L2 cache subsystem was a downgrade when compared to the Pentium Pros. It is a single-core microprocessor.

<span class="mw-page-title-main">Pentium III</span> Line of desktop and mobile microprocessors produced by Intel

The Pentium III brand refers to Intel's 32-bit x86 desktop and mobile CPUs based on the sixth-generation P6 microarchitecture introduced on February 28, 1999. The brand's initial processors were very similar to the earlier Pentium II-branded processors. The most notable differences were the addition of the Streaming SIMD Extensions (SSE) instruction set, and the introduction of a controversial serial number embedded in the chip during manufacturing. The Pentium III is also a single-core processor.

<span class="mw-page-title-main">Pentium Pro</span> Sixth-generation x86 microprocessor by Intel

The Pentium Pro is a sixth-generation x86 microprocessor developed and manufactured by Intel and introduced on November 1, 1995. It introduced the P6 microarchitecture and was originally intended to replace the original Pentium in a full range of applications. Later, it was reduced to a more narrow role as a server and high-end desktop processor. The Pentium Pro was also used in supercomputers, most notably ASCI Red, which used two Pentium Pro CPUs on each computing nodes and was the first computer to reach over one teraFLOPS in 1996, topping the number one spot in the TOP500 list from 1997 to 2000.

<span class="mw-page-title-main">Pentium M</span> Family of Intel microprocessors

The Pentium M is a family of mobile 32-bit single-core x86 microprocessors 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. 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.

Tejas was a code name for Intel's microprocessor, which was to be a successor to the latest Pentium 4 with the Prescott core and was sometimes referred to as Pentium V. Jayhawk was a code name for its Xeon counterpart. The cancellation of the processors in May 2004 underscored Intel's historical transition of its focus on single-core processors to multi-core processors.

<span class="mw-page-title-main">Xeon</span> Line of Intel server and workstation processors

Xeon is a brand of x86 microprocessors designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server, and embedded markets. It was introduced in June 1998. Xeon processors are based on the same architecture as regular desktop-grade CPUs, but have advanced features such as support for error correction code (ECC) memory, higher core counts, more PCI Express lanes, support for larger amounts of RAM, larger cache memory and extra provision for enterprise-grade reliability, availability and serviceability (RAS) features responsible for handling hardware exceptions through the Machine Check Architecture (MCA). They are often capable of safely continuing execution where a normal processor cannot due to these extra RAS features, depending on the type and severity of the machine-check exception (MCE). Some also support multi-socket systems with two, four, or eight sockets through use of the Ultra Path Interconnect (UPI) bus, which replaced the older QuickPath Interconnect (QPI) bus.

The NetBurst microarchitecture, called P68 inside Intel, was the successor to the P6 microarchitecture in the x86 family of central processing units (CPUs) made by Intel. The first CPU to use this architecture was the Willamette-core Pentium 4, released on November 20, 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst. In mid-2001, Intel released the Foster core, which was also based on NetBurst, thus switching the Xeon CPUs to the new architecture as well. Pentium 4-based Celeron CPUs also use the NetBurst architecture.

The Intel Core microarchitecture is a multi-core processor microarchitecture launched by Intel in mid-2006. It is a major evolution over the Yonah, the previous iteration of the P6 microarchitecture series which started in 1995 with Pentium Pro. It also replaced the NetBurst microarchitecture, which suffered from high power consumption and heat intensity due to an inefficient pipeline designed for high clock rate. In early 2004 the new version of NetBurst (Prescott) needed very high power to reach the clocks it needed for competitive performance, making it unsuitable for the shift to dual/multi-core CPUs. On May 7, 2004 Intel confirmed the cancellation of the next NetBurst, Tejas and Jayhawk. Intel had been developing Merom, the 64-bit evolution of the Pentium M, since 2001, and decided to expand it to all market segments, replacing NetBurst in desktop computers and servers. It inherited from Pentium M the choice of a short and efficient pipeline, delivering superior performance despite not reaching the high clocks of NetBurst.

<span class="mw-page-title-main">Yonah (microprocessor)</span> Code name of Intels first generation 65 nm process CPU cores

Yonah is the code name of Intel's first generation 65 nm process CPU cores, based on cores of the earlier Banias / Dothan Pentium M microarchitecture. Yonah CPU cores were used within Intel's Core Solo and Core Duo mobile microprocessor products. SIMD performance on Yonah improved through the addition of SSE3 instructions and improvements to SSE and SSE2 implementations; integer performance decreased slightly due to higher latency cache. Additionally, Yonah included support for the NX bit.

<span class="mw-page-title-main">Pentium</span> Brand of discontinued microprocessors produced by Intel

Pentium is a discontinued series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium was first released on March 22, 1993. The name "Pentium" is originally derived from the Greek word pente (πεντε), meaning "five", a reference to the prior numeric naming convention of Intel's 80x86 processors (8086–80486), with the Latin ending -ium since the processor would otherwise have been named 80586 using that convention.

<span class="mw-page-title-main">Pentium Dual-Core</span> Line of CPUs by Intel

The Pentium Dual-Core brand was used for mainstream x86-architecture microprocessors from Intel from 2006 to 2009, when it was renamed to Pentium. The processors are based on either the 32-bit Yonah or 64-bit Merom-2M, Allendale, and Wolfdale-3M core, targeted at mobile or desktop computers.

<span class="mw-page-title-main">Conroe (microprocessor)</span> Code name for several Intel processors

Conroe is the code name for many Intel processors sold as Core 2 Duo, Xeon, Pentium Dual-Core and Celeron. It was the first desktop processor to be based on the Core microarchitecture, replacing the NetBurst microarchitecture based Cedar Mill processor. It has product code 80557, which is shared with Allendale and Conroe-L that are very similar but have a smaller L2 cache. Conroe-L has only one processor core and a new CPUID model. The mobile version of Conroe is Merom, the dual-socket server version is Woodcrest, the quad-core desktop version is Kentsfield and the quad-core dual-socket version is Clovertown. Conroe was replaced by the 45 nm Wolfdale processor.

<span class="mw-page-title-main">Wolfdale (microprocessor)</span>

Wolfdale is the code name for a processor from Intel that is sold in varying configurations as Core 2 Duo, Celeron, Pentium and Xeon. In Intel's Tick-Tock cycle, the 2007/2008 "Tick" was Penryn microarchitecture, the shrink of the Merom microarchitecture to 45 nanometers as CPUID model 23. This replaced the Conroe processor with Wolfdale.

<span class="mw-page-title-main">Yorkfield</span>

Yorkfield is the code name for some Intel processors sold as Core 2 Quad and Xeon. In Intel's Tick-Tock cycle, the 2007/2008 "Tick" was Penryn microarchitecture, the shrink of the Core microarchitecture to 45 nanometers as CPUID model 23, replacing Kentsfield, the previous model.

In Intel's Tick-Tock cycle, the 2007/2008 "Tick" was the shrink of the Core microarchitecture to 45 nanometers as CPUID model 23. In Core 2 processors, it is used with the code names Penryn, Wolfdale and Yorkfield, some of which are also sold as Celeron, Pentium and Xeon processors. In the Xeon brand, the Wolfdale-DP and Harpertown code names are used for LGA 771 based MCMs with two or four active Wolfdale cores.

References

  1. "Pentium® Pro Processor at 150 MHz, 166 MHz, 180 MHz and 200 MHz" (PDF). Intel Corporation. November 1995. p. 1. Archived from the original (PDF) on April 12, 2016.
  2. Hutchings, Ben (September 28, 2015). "Defaulting to i686 for the Debian i386 architecture". debian-devel (Mailing list).
  3. Gwennap, Linley (February 16, 1995). "Intel's P6 Uses Decoupled Scalar Design" (PDF). Microprocessor Report. 9 (2).
  4. Pentium and Pentium Pro Processors and Related Products. Intel Corporation. December 1995. pp. 1–10. ISBN   1-55512-251-5.
  5. Brey, Barry (2009). The Intel Microprocessors (PDF) (8th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall. p. 754. ISBN   978-0-13-502645-8.
  6. 1 2 Shimpi, Anand Lal (July 21, 2004). "Intel's 90nm Pentium M 755: Dothan Investigated". AnandTech .
  7. "PAE - Community Help Wiki". Ubuntu Help.
  8. This Does Not Compute. Can You Install Windows 10 on a Pentium II?. YouTube. Section starts at 32:35.
  9. "Pat Gelsinger talk at Stanford, Jun 7th 2006". Archived from the original on June 3, 2011.