The Pentium III[2] (marketed as Intel Pentium III Processor, informally PIII or P3) brand refers to Intel's 32-bitx86 desktop and mobile CPUs based on the sixth-generation P6 microarchitecture introduced on February 28, 1999.[citation needed] 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 (to accelerate floating point and parallel calculations), and the introduction of a controversial serial number embedded in the chip during manufacturing. The Pentium III is also a single-core processor.
Even after the release of the Pentium 4 in late 2000, the Pentium III continued to be produced with new models introduced up until early 2003. They were then discontinued in April 2004 for desktop units[3] and May 2007 for mobile units.[1]
A Pentium III Katmai SECC2 cartridge with heatsink removed.Katmai Die shot
The first Pentium III variant was the Katmai (Intel product code 80525). It was a further development of the Deschutes Pentium II. The Pentium III saw an increase of 2 million transistors over the Pentium II. The differences were the addition of execution units and SSE instruction support, and an improved L1 cache controller[citation needed] (the L2 cache controller was left unchanged, as it would be fully redesigned for Coppermine anyway), which were responsible for the minor performance improvements over the "Deschutes" Pentium IIs. It was first released at speeds of 450 and 500MHz on February 28, 1999. Two more versions were released: 550MHz on May 17, 1999 and 600MHz on August 2, 1999. On September 27, 1999, Intel released the 533B and 600B running at 533 & 600MHz respectively. The 'B' suffix indicated that it featured a 133MT/s FSB, instead of the 100MT/s FSB of prior models.
The Katmai contains 9.5 million transistors, not including the 512 Kbytes L2 cache (which adds 25 million transistors), and has dimensions of 12.3mm by 10.4mm (128mm2). It is fabricated in Intel's P856.5 process, a 250 nm complementary metal–oxide–semiconductor (CMOS) process with five levels of aluminum interconnect.[4] The Katmai used the same slot-based design as the Pentium II but with the newer Slot 1 Single Edge Contact Cartridge (SECC) 2 that allowed direct CPU core contact with the heat sink. There have been some early models of the PentiumIII with 450 and 500MHz packaged in an older SECC cartridge intended for original equipment manufacturers (OEMs).
A notable stepping level for enthusiasts was SL35D. This version of Katmai was officially rated for 450MHz, but often contained cache chips for the 600MHz model and thus usually can run at 600MHz.
Coppermine
A 900 MHz Coppermine FC-PGA Pentium III.Coppermine Die shot
The second version, codenamed Coppermine (Intel product code: 80526), was released on October 25, 1999 running at 500, 533, 550, 600, 650, 667, 700, and 733MHz. From December 1999 to May 2000, Intel released Pentium IIIs running at speeds of 750, 800, 850, 866, 900, 933 and 1000MHz (1GHz). Both 100MT/s FSB and 133MT/s FSB models were made. For models that were already available with the same frequency, an "E" was appended to the model name to indicate cores using the new 180nm fabrication process. An additional "B" was later appended to designate 133MHz FSB models, resulting in an "EB" suffix. In overall performance, Coppermine had a small advantage over the Advanced Micro Devices (AMD) Athlons it was released against, which was reversed when AMD applied their own die shrink and added an on-die L2 cache to the Athlon. Athlon held the advantage in floating-point intensive code, while the Coppermine could perform better when SSE optimizations were used, but in practical terms there was little difference in how the two chips performed, clock-for-clock. However, AMD were able to clock the Athlon higher, reaching speeds of 1.2GHz before the launch of the Pentium 4.
In performance, Coppermine arguably marked a bigger step than Katmai by introducing an on-chip L2 cache, which Intel names Advanced Transfer Cache (ATC). The ATC operates at the core clock rate and has a capacity of 256KB, twice that of the on-chip cache formerly on Mendocino Celerons. It is eight-way set-associative and is accessed via a Double Quad Word Wide 256-bit bus, four times as wide as Katmai's. Further, latency was dropped to a quarter compared to Katmai. Another marketing term by Intel was Advanced System Buffering, which encompassed improvements to better take advantage of a 133MT/s system bus. These include 6 fill buffers (vs. 4 on Katmai), 8 bus queue entries (vs. 4 on Katmai) and 4 write-back buffers (vs. 1 on Katmai).[5] Under competitive pressure from the AMDAthlon, Intel reworked the internals, finally removing some well-known pipeline stalls.[citation needed] As a result, applications affected by the stalls ran faster on Coppermine by up to 30%.[citation needed] The Coppermine contained 29 million transistors and was fabricated in a 180nm process.
The Coppermine was available in 370-pin FC-PGA or FC-PGA2 for use with Socket 370, or in SECC2 for Slot 1 (all speeds except 900 and 1100). FC-PGA and Slot 1 Coppermine CPUs have an exposed die, however most higher frequency SKUs starting with the 866MHz model were also produced in FC-PGA2 variants that feature an integrated heat spreader (IHS). This in itself did not improve thermal conductivity, since it added another layer of metal and thermal paste between the die and the heatsink, but it greatly assisted in holding the heatsink flat against the die. Earlier Coppermines without the IHS made heatsink mounting challenging.[6] If the heatsink was not situated flat against the die, heat transfer efficiency was greatly reduced. Some heatsink manufacturers began providing pads on their products, similar to what AMD did with the "Thunderbird" Athlon to ensure that the heatsink was mounted flatly. The enthusiast community went so far as to create shims to assist in maintaining a flat interface.[7]
A 1.13GHz version (S-Spec SL4HH) was released in mid-2000 but famously recalled after a collaboration between HardOCP and Tom's Hardware[8] discovered various instabilities with the operation of the new CPU speed grade. The Coppermine core was unable to reliably reach the 1.13GHz speed without various tweaks to the processor's microcode, effective cooling, higher voltage (1.75 V vs. 1.65 V), and specifically validated platforms.[8] Intel only officially supported the processor on its own VC820 i820-based motherboard, but even this motherboard displayed instability in the independent tests of the hardware review sites. In benchmarks that were stable, performance was shown to be sub-par, with the 1.13GHz CPU equalling a 1.0GHz model. Tom's Hardware attributed this performance deficit to relaxed tuning of the CPU and motherboard to improve stability.[9] Intel needed at least six months to resolve the problems using a new cD0 stepping and re-released 1.1GHz and 1.13GHz versions in 2001.
Microsoft's Xboxgame console uses a variant of the Pentium III/Mobile Celeron family in a Micro-PGA2 form factor. The sSpec designator of the chips is SL5Sx, which makes it more similar to the Mobile Celeron Coppermine-128 processor. It shares with the Coppermine-128 Celeron its 128KB L2 cache, and 180nm process technology, but keeps the 8-way cache associativity from the Pentium III.[10]
Although its codename could give the impression that it used copper interconnects, in reality, its interconnects were aluminium.
Coppermine T
This revision is an intermediate step between Coppermine and Tualatin, with support for lower-voltage system logic present on the latter but core power within previously defined voltage specs of the former so it could work in older system boards.
Intel used the latest FC-PGA2 Coppermines with the cD0 stepping and modified them so that they worked with low voltage system bus operation at 1.25 V AGTL as well as normal 1.5 V AGTL+ signal levels, and would auto detect differential or single-ended clocking. This modification made them compatible to the latest generation Socket 370 boards supporting Tualatin CPUs while maintaining compatibility with older Socket 370 boards. The Coppermine T also had two way symmetrical multiprocessing capabilities, but only in Tualatin boards.
They can be distinguished from Tualatin processors by their part numbers, which include the digits "80533", e.g. the 1133MHz SL5QK P/N is RK80533PZ006256, while the 1000MHz SL5QJ P/N is RK80533PZ001256.[11]
Tualatin
A 1.13 GHz FC-PGA2 Tualatin-256 Intel Pentium III-T.Tualatin die shot
The third revision, Tualatin (80530), was a trial for Intel's new 130nm process. Tualatin-based Pentium IIIs were released during 2001 until early 2002 at speeds of 1.0, 1.13, 1.2, 1.26, 1.33 and 1.4GHz. A basic shrink of Coppermine, no new features were added, except for added data prefetch logic similar to Pentium 4 and Athlon XP for potentially better use of the L2 cache, although its use compared to these newer CPUs is limited due to the relatively smaller FSB bandwidth (FSB was still kept at 133MHz).[12] Variants with 256 and 512KB L2 cache were produced, the latter being dubbed Pentium III-S; this variant was mainly intended for low-power consumption servers and also exclusively featured SMP support within the Tualatin line.
Although the Socket 370 designation was kept, the use of 1.25 AGTL signaling in place of 1.5 V AGTL+ rendered prior motherboards incompatible.[12] This confusion carried over to the chipset naming, where only the B-stepping of the i815 chipset was compatible with Tualatin processors.[13] A new VRM guideline was also designed by Intel, version 8.5, which required finer voltage steps and debuted load line Vcore (in place of fixed voltage regardless of current on 8.4).[14][15][16] Some motherboard manufacturers would mark the change with blue sockets (instead of white), and were often also backwards compatible with Coppermine CPUs.
The Tualatin also formed the basis for the highly popular Pentium III-M mobile processor, which became Intel's front-line mobile chip (the Pentium 4 drew significantly more power, and so was not well-suited for this role) for the next two years. The chip offered a good balance between power consumption and performance, thus finding a place in both performance notebooks and the "thin and light" category.
The Tualatin-based Pentium III performed well in some applications compared to the fastest Willamette-based Pentium 4, and even the Thunderbird-based Athlons. Despite this, its appeal was limited due to the aforementioned incompatibility with existing systems, and Intel's only officially supported chipset for Tualatins, the i815, could only handle 512 MB RAM as opposed to 1 GB of registered RAM with the older, incompatible 440BX chipset. However, the enthusiast community found a way to run Tualatins on then-ubiquitous BX chipset based boards, although it was often a non-trivial task and required some degree of technical skills.
Tualatin-based Pentium III CPUs can usually be visually distinguished from Coppermine-based processors by the metal integrated heat-spreader (IHS) fixed on top of the package. However, the last models of Coppermine Pentium IIIs also featured the IHS — the integrated heat spreader is actually what distinguishes the FC-PGA2 package from the FC-PGA — both are for Socket 370 motherboards.[17]
Before the addition of the heat spreader, it was sometimes difficult to install a heatsink on a Pentium III. One had to be careful not to put force on the core at an angle because doing so would cause the edges and corners of the core to crack and could destroy the CPU. It was also sometimes difficult to achieve a flat mating of the CPU and heatsink surfaces, a factor of critical importance to good heat transfer. This became increasingly challenging with the Socket 370 CPUs, compared with their Slot 1 predecessors, because of the force required to mount a socket-based cooler and the narrower, 2-sided mounting mechanism (Slot 1 featured 4-point mounting). As such, and because the 130nm Tualatin had an even smaller core surface area than the 180nm Coppermine, Intel installed the metal heatspreader on Tualatin and all future desktop processors.
The Tualatin core was named after the Tualatin Valley and Tualatin River in Oregon, where Intel has large manufacturing and design facilities.
Pentium III's SSE implementation
Slot 1 Pentium III CPU mounted on a motherboard
Since Katmai was built in the same 250nm process as Pentium II "Deschutes", it had to implement Streaming SIMD Extensions (SSE) using minimal silicon.[18] To achieve this goal, Intel implemented the 128-bit architecture by double-cycling the existing 64-bit data paths and by merging the SIMD-FP multiplier unit with the x87 scalar FPU multiplier into a single unit. To utilize the existing 64-bit data paths, Katmai issues each SIMD-FP instruction as two μops. To compensate partially for implementing only half of SSE's architectural width, Katmai implements the SIMD-FP adder as a separate unit on the second dispatch port. This organization allows one half of a SIMD multiply and one half of an independent SIMD add to be issued together bringing the peak throughput back to four floating point operations per cycle — at least for code with an even distribution of multiplies and adds.[4][19]
The issue was that Katmai's hardware-implementation contradicted the parallelism model implied by the SSE instruction-set. Programmers faced a code-scheduling dilemma: "Should the SSE-code be tuned for Katmai's limited execution resources, or should it be tuned for a future processor with more resources?" Katmai-specific SSE optimizations yielded the best possible performance from the Pentium III family but was suboptimal for Coppermine onwards as well as future Intel processors, such as the Pentium 4 and Core series.
The Pentium III was the first x86 CPU to include a unique, retrievable, identification number, called Processor Serial Number (PSN). A Pentium III's PSN can be read by software[20] through the CPUID instruction if this feature has not been disabled through the BIOS.
On November 29, 1999, the Science and Technology Options Assessment (STOA) Panel of the European Parliament, following their report on electronic surveillance techniques asked parliamentary committee members to consider legal measures that would "prevent these chips from being installed in the computers of European citizens."[21]
Intel eventually removed the PSN feature from Tualatin-based Pentium IIIs, and the feature was absent in Pentium 4 and Pentium M.
A largely equivalent feature, the Protected Processor Identification Number (PPIN) was later added to x86 CPUs with little public notice, starting with Intel's Ivy Bridge architecture and compatible Zen 2 AMD CPUs. It is implemented as a set of model-specific registers and is useful for machine check exception handling.[22]
Pentium III RNG (Random Number Generator)
A new feature was added to the Pentium III: a hardware-based random number generator.[23][24] It has been described as "several oscillators combine their outputs and that odd waveform is sampled asynchronously."[25]
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.
Duron is a line of budget x86-compatible microprocessors manufactured by AMD and released on June 19, 2000. Duron was intended to be a lower-cost offering to complement AMD's then mainstream performance Athlon processor line, and it also competed with rival chipmaker Intel's Pentium III and Celeron processor offerings. The Duron brand name was retired in 2004, succeeded by the AMD's Sempron line of processors as their budget offering.
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.
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.
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.
The Athlon 64 is a ninth-generation, AMD64-architecture microprocessor produced by Advanced Micro Devices (AMD), released on September 23, 2003. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP. The Athlon 64 was the second processor to implement the AMD64 architecture and the first 64-bit processor targeted at the average consumer. Variants of the Athlon 64 have been produced for Socket 754, Socket 939, Socket 940, and Socket AM2. It was AMD's primary consumer CPU, and primarily competed with Intel's Pentium 4, especially the Prescott and Cedar Mill core revisions.
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 K6-2 is an x86 microprocessor introduced by AMD on May 28, 1998, and available in speeds ranging from 266 to 550 MHz. An enhancement of the original K6, the K6-2 introduced AMD's 3DNow! SIMD instruction set and an upgraded system-bus interface called Super Socket 7, which was backward compatible with older Socket 7 motherboards. It was manufactured using a 250 nanometer process, ran at 2.2 volts, and had 9.3 million transistors.
The K6-III was an x86 microprocessor line manufactured by AMD that launched on February 22, 1999. The launch consisted of both 400 and 450 MHz models and was based on the preceding K6-2 architecture. Its improved 256 KB on-chip L2 cache gave it significant improvements in system performance over its predecessor the K6-2. The K6-III was the last processor officially released for desktop Socket 7 systems, however later mobile K6-III+ and K6-2+ processors could be run unofficially in certain socket 7 motherboards if an updated BIOS was made available for a given board. The Pentium III processor from Intel launched 6 days later.
Socket 370, also known as PGA370, is a CPU socket first used by Intel for Pentium III and Celeron processors to first complement and later replace the older Slot 1 CPU interface on personal computers. The "370" refers to the number of pin holes in the socket for CPU pins.
Slot 1 refers to the physical and electrical specification for the connector used by some of Intel's microprocessors, including the Pentium Pro, Celeron, Pentium II and the Pentium III. Both single and dual processor configurations were implemented.
Sempron has been the marketing name used by AMD for several different budget desktop CPUs, using several different technologies and CPU socket formats. The Sempron replaced the AMD Duron processor and competed against Intel's Celeron series of processors. AMD coined the name from the Latin semper, which means "always", to suggest the Sempron is suitable for "daily use, practical, and part of everyday life". The last Semprons were launched in April 2014. The brand was retired with the launch of the AMD A-Series APUs.
Pentium D is a range of desktop 64-bit x86-64 processors based on the NetBurst microarchitecture, which is the dual-core variant of the Pentium 4 manufactured by Intel. Each CPU comprised two cores. The brand's first processor, codenamed Smithfield and manufactured on the 90 nm process, was released on May 25, 2005, followed by the 65 nm Presler nine months later. The core implementation on the 90 nm "Smithfield" and later 65 nm "Presler" are designed differently but are functionally the same. The 90 nm "Smithfield" contains a single die, with two adjoined but functionally separate CPU cores cut from the same wafer. The later 65 nm "Presler" utilized a multi-chip module package, where two discrete dies each containing a single core reside on the CPU substrate. Neither the 90nm "Smithfield" nor the 65 nm "Presler" were capable of direct core to core communication, relying instead on the northbridge link to send information between the 2 cores.
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. 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.
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.
The Intel 440BX is a chipset from Intel, supporting Pentium II, Pentium III, and Celeron processors. It is also known as the i440BX and was released in April 1998. The official part number is 82443BX.
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.
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.
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