Pentium D
Encyclopedia
The Pentium D brand refers to two series of desktop dual-core 64-bit
x86-64
microprocessor
s with the NetBurst microarchitecture manufactured by Intel
. Each CPU comprised two dies
, each containing a single core, residing next to each other on a multi-chip module
package. The brand's first processor, codenamed Smithfield, was released by Intel on May 25, 2005. Nine months later, Intel introduced its successor, codenamed Presler, but without offering significant upgrades in design, still resulting in relatively high power consumption. By 2004, the NetBurst processors reached a clock speed barrier at 3.8 GHz due to a thermal (and power) limit exemplified by the Presler's 130 watt
thermal design power
(a higher TDP requires additional cooling that can be prohibitively noisy or expensive). The future belonged to more energy efficient and slower clocked dual-core CPUs on a single die
instead of two. The final shipment date of the dual die Presler chips was August 8, 2008, which marked the end of the Pentium D brand and also the NetBurst microarchitecture.
applications typical in transcoding of audio and video, compressing
, photo and video editing
and rendering
, and ray-tracing. Single-threaded applications alone, including most older games, do not benefit from the second core of dual-core CPU compared to equally clocked single-core CPU. Nevertheless, the dual-core CPU is useful to run both the client and server processes of a game without noticeable lag in either thread, as each instance could be running on a different core. Furthermore, multi-threaded games benefit from the Twin-core CPUs.
As of 2008 many business applications are not optimized for multiple cores. They run at similar speed when not multitasking on the Pentium D or older Pentium 4
branded CPUs at the same clock speed. However, in multitasking
environments such as BSD
, Linux
, Microsoft Windows
operating system
s, other processes are often running at the same time; if they require significant CPU time, each core of the Pentium D branded processor can handle different programs, improving overall processing speed over its single-core Pentium 4 counterpart.
In April 2005, Intel's biggest rival, AMD, had x86 dual-core microprocessor
s intended for workstation
s and server
s on the market, and was poised to launch a comparable product intended for desktop computer
s. As a response, Intel developed Smithfield, the first x86 dual-core microprocessor intended for desktop computers, beating AMD's Athlon 64 X2
by a few weeks. Intel first launched Smithfield on April 16, 2005 in the form of the 3.2 GHz
Hyper-threading
enabled Pentium Extreme Edition 840. On May 26, 2005, Intel launched the mainstream Pentium D branded processor lineup with initial clock speeds of 2.8, 3.0, and 3.2 GHz with model numbers of 820, 830, and 840 respectively. In March 2006, Intel launched the last Smithfield processor, the entry-level Pentium D 805, clocked at 2.66 GHz with a 533 MT/s
bus. The relatively cheap 805 was found to be highly overclockable; 3.5 GHz was often possible with good air cooling. Running it at over 4 GHz was possible with water cooling, and at this speed the 805 outperformed the top-of-the-line processors (May 2006) from both major CPU manufacturers (the AMD Athlon 64
FX-60 and Intel Pentium Extreme Edition 965) in many benchmarks including power consumption.
The 805 and 820 models had a 95 watt TDP
. All other models were rated at 130 watt.
All Smithfield processors were made of two 90 nm
Prescott cores, next to each other on a single die
with 1 MB
of Level 2 (L2) cache per core. Hyper-threading was disabled in all Pentium D 8xx-series Smithfields with the exception of the Pentium Extreme Edition 840. Smithfield did not support Intel VT-x—Intel's x86 virtualization
(formerly Vanderpool).
All Pentium D processors supported Intel 64 (formerly EM64T), XD Bit, and were manufactured for the LGA 775 form factor. The only motherboard
s guaranteed to work with the Pentium D (and Extreme Edition) branded CPUs were those based on the 945-, 955-, 965- and 975-series Intel chipsets, as well as the nForce 4 SLI Intel Edition
and ATI
Radeon Xpress
. The Pentium D 820 did not work with the nForce 4 SLI Intel Edition chipset due to some power design issues, though they were rectified in the X16 version. The 915- and 925-series chipsets did not work at all with the Smithfields, as they did not support more than one core (to prevent motherboard manufacturers from using them for Xeon
branded motherboards, as had happened with the 875P chipset). The 865- and 875-series chipsets supported multiprocessing. Motherboards with them might be Pentium D compatible with an updated BIOS
.
A week after its launch, Intel officially denied a report in Computerworld Today Australia that the Pentium D branded CPUs included "secret" digital rights management
features in their hardware that could be utilized by Microsoft Windows
and other operating systems, but was not publicly disclosed. While Intel admitted that there were some DRM technologies in the 945- and 955-series chipsets, it stated that the extent of the technologies was exaggerated, and that the technologies in question had been present in Intel's chipsets since the 875P.
-process cores found also in Pentium 4
branded Cedar Mill CPUs. Presler introduced the 'multi-chip module, or MCM, which consisted of two single-core dies
placed next to each other on the same substrate package. This allowed Intel to produce these processors at a reduced production cost as a result of higher yields. Presler was supported by the same chipsets as Smithfield. It was produced using 65 nm
technology similar to Yonah. Presler communicated with the system using an 800 MT/s FSB, and its two cores communicated also using the FSB, just as in Smithfield. Presler also included Intel VT-x (formerly Vanderpool) –although this was limited to the 9x0 models, and not in the 9x5 models– Intel 64, XD bit, and EIST (Enhanced Intel SpeedStep
Technology). Presler was released in the first quarter of 2006 with a 2x2 MB Level 2 cache. Its models included 915, 920, 925, 930, 935, 940, 945, 950 and 960 (with a respective 2.8, 2.8, 3.0, 3,0, 3.2, 3.2, 3.4, 3.4, and 3.6 GHz clock frequency).
All steppings of Presler models 915, 920, 925, 930, and 935, as well as the C1, D0 steppings of 940, 945, and 950 and the 960 D0 stepping were rated at a 95 watt TDP
. All other models (i.e. certain models with 3.2 GHz or faster clock frequencies) were rated at 130 watt — a 37% increase in power consumption.
[*] The first batch of Presler processors (revision B1) had the EIST feature turned off by a microcode update because of stability issues. That affected only its power consumption, when idle, and thermal dissipation. Chips with working EIST started shipping in Q2 2006. They had a different S-Spec number which can be found in Intel errata documentation.
enabled, thus any operating system saw four logical processors (two physical and two virtual). It also had an unlocked multiplier to allow overclocking. It was initially released as Intel Pentium Extreme Edition 840 at 3.20 GHz, in early 2005, at a price point of $999.99 (OEM
price) or $1,200 (retail). The only chipsets that worked with the Extreme Edition 840 were Intel's 955X, NVIDIA's nForce4 SLI Intel Edition, and ATi Radeon Xpress 200. Using a Pentium Extreme Edition branded CPU with an Intel 945-series chipset will disable Hyper-threading effectively turning the processor into a Pentium D branded equivalent.
FSB compared to the 800 MT/s in the non-Extreme edition. A second version, the 965 at 3.73 GHz followed in March 2006. Both CPU's also feature Hyper-Threading Technology. Many overclockers, however, had been able to overclock the core to 4.26 GHz using air cooling simply by raising the unlocked CPU multiplier.
The 'Presler Extreme Edition' would run only combined with the Intel 975X chipset (it could also work with the 955X chipset, though this combination was not supported by Intel). The i975X featured the ICH7R southbridge
and supported all LGA 775 (Socket T) Pentium 4, Pentium D, and Pentium Extreme Edition branded processors.
s with the Core microarchitecture released as dual- and quad-core microprocessors branded Duo, Quad, and Extreme.
link is point-to-point and the only real requirement is that it is fast enough to keep the CPU fed with data from memory
.
When assessing the Pentium D, it is important to note that it is essentially two CPUs in the same package and that it will face the same bus contention
issues as a pair of Xeon
s prior to the Dual Independent Bus architecture introduced with the Dual-Core Dempsey Xeons. To use a crude analogy one could say that instead of using a single cable between CPU and north bridge, one must use a Y-splitter. Leaving aside advanced issues such as cache coherency
, each core can only use half of the 800 MT/s FSB bandwidth when under heavy load.
, had some significant advantages over the Pentium D, such as an integrated memory controller
, a high-speed HyperTransport
bus, a shorter pipeline (12 stages compared to the Pentium D's 31), and better floating point
performance, more than offsetting the difference in raw clock speed. Also, while the Athlon 64 X2 inherited mature multi-core
control logic from the multi-core Opteron, the Pentium D was seemingly rushed to production and essentially consisted of two CPUs in the same package. Indeed, shortly after the launch of the mainstream Pentium D branded processors (26 May 2005) and the Athlon 64 X2 (31 May 2005), a consensus arose that AMD's implementation of multi-core
was superior to that of the Pentium D. As a result of this and other factors, AMD surpassed Intel in CPU sales at US retail stores for a period of time, although Intel retained overall market leadership because of its exclusive relationships with direct sellers such as Dell.
architecture, which was itself based upon the Pentium III
). The newer Pentium Dual-Core processors give off considerably less heat (65 watt) than the Pentium D (95 or 130 watt). They also run at lower clock rates, only have up to 2 MB L2 Cache memory while the Pentium D has up to 2x2 MB, and they lack Hyper-threading. On the other hand, the Pentium Dual-Core has a wider execution unit (4 issues wide compared to the Pentium D's 3) and its 14 stages-long pipeline is less than half the length of the Pentium D's, allowing it to outperform the Pentium D in most applications.
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
x86-64
X86-64
x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...
microprocessor
Microprocessor
A 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 NetBurst microarchitecture manufactured by Intel
Intel Corporation
Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...
. Each CPU comprised two dies
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
, each containing a single core, residing next to each other on a multi-chip module
Multi-Chip Module
A multi-chip module is a specialized electronic package where multiple integrated circuits , semiconductor dies or other discrete components are packaged onto a unifying substrate, facilitating their use as a single component...
package. The brand's first processor, codenamed Smithfield, was released by Intel on May 25, 2005. Nine months later, Intel introduced its successor, codenamed Presler, but without offering significant upgrades in design, still resulting in relatively high power consumption. By 2004, the NetBurst processors reached a clock speed barrier at 3.8 GHz due to a thermal (and power) limit exemplified by the Presler's 130 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
thermal design power
Thermal Design Power
The 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...
(a higher TDP requires additional cooling that can be prohibitively noisy or expensive). The future belonged to more energy efficient and slower clocked dual-core CPUs on a single die
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
instead of two. The final shipment date of the dual die Presler chips was August 8, 2008, which marked the end of the Pentium D brand and also the NetBurst microarchitecture.
Pentium D/Extreme Edition
The twin-core CPU is capable of running multi-threadedThread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
applications typical in transcoding of audio and video, compressing
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
, photo and video editing
Video editing software
Video editing software, is application software which handles the post-production video editing of digital video sequences on a computer non-linear editing systems...
and rendering
Rendering (computer graphics)
Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
, and ray-tracing. Single-threaded applications alone, including most older games, do not benefit from the second core of dual-core CPU compared to equally clocked single-core CPU. Nevertheless, the dual-core CPU is useful to run both the client and server processes of a game without noticeable lag in either thread, as each instance could be running on a different core. Furthermore, multi-threaded games benefit from the Twin-core CPUs.
As of 2008 many business applications are not optimized for multiple cores. They run at similar speed when not multitasking on the Pentium D or older Pentium 4
Pentium 4
Pentium 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...
branded CPUs at the same clock speed. However, in multitasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
environments such as BSD
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s, other processes are often running at the same time; if they require significant CPU time, each core of the Pentium D branded processor can handle different programs, improving overall processing speed over its single-core Pentium 4 counterpart.
| Intel Pentium D processor family | ||||
|---|---|---|---|---|
| Original logo | New logo | Desktop | ||
| Code-named | Manufacturing process | Date released | ||
 |
 |
Smithfield Presler |
90 nm 65 nm |
May 2005 Jan 2006 |
 |
 |
Smithfield XE Presler XE |
90 nm 65 nm |
May 2005 Jan 2006 |
| List of Intel Pentium D microprocessors | ||||
Smithfield
Microprocessor
A 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 intended for workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
s and server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
s on the market, and was poised to launch a comparable product intended for desktop computer
Desktop computer
A desktop computer is a personal computer in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers are designed to lay flat on the desk, while modern towers stand upright...
s. As a response, Intel developed Smithfield, the first x86 dual-core microprocessor intended for desktop computers, beating AMD's Athlon 64 X2
Athlon 64 X2
The Athlon 64 X2 is the first dual-core desktop CPU designed by AMD. It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with another functional core on one die, and connecting both via a shared dual-channel memory controller/north bridge and...
by a few weeks. Intel first launched Smithfield on April 16, 2005 in the form of the 3.2 GHz
GHZ
GHZ or GHz may refer to:# Gigahertz .# Greenberger-Horne-Zeilinger state — a quantum entanglement of three particles.# Galactic Habitable Zone — the region of a galaxy that is favorable to the formation of life....
Hyper-threading
Hyper-threading
Hyper-threading is Intel's term for its simultaneous multithreading implementation in its Atom, Intel Core i3/i5/i7, Itanium, Pentium 4 and Xeon CPUs....
enabled Pentium Extreme Edition 840. On May 26, 2005, Intel launched the mainstream Pentium D branded processor lineup with initial clock speeds of 2.8, 3.0, and 3.2 GHz with model numbers of 820, 830, and 840 respectively. In March 2006, Intel launched the last Smithfield processor, the entry-level Pentium D 805, clocked at 2.66 GHz with a 533 MT/s
Megatransfer
In computer technology, transfers per second and its more common derivatives gigatransfers per second and megatransfers per second are informal language that refer to the number of operations transferring data that occur in each second in some given data-transfer channel. It is also known as...
bus. The relatively cheap 805 was found to be highly overclockable; 3.5 GHz was often possible with good air cooling. Running it at over 4 GHz was possible with water cooling, and at this speed the 805 outperformed the top-of-the-line processors (May 2006) from both major CPU manufacturers (the AMD Athlon 64
Athlon 64
The Athlon 64 is an eighth-generation, AMD64-architecture microprocessor produced by AMD, released on September 23, 2003. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP...
FX-60 and Intel Pentium Extreme Edition 965) in many benchmarks including power consumption.
The 805 and 820 models had a 95 watt TDP
Thermal Design Power
The 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...
. All other models were rated at 130 watt.
All Smithfield processors were made of two 90 nm
90 nanometer
The 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....
Prescott cores, next to each other on a single die
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
with 1 MB
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
of Level 2 (L2) cache per core. Hyper-threading was disabled in all Pentium D 8xx-series Smithfields with the exception of the Pentium Extreme Edition 840. Smithfield did not support Intel VT-x—Intel's x86 virtualization
X86 virtualization
In computing, x86 virtualization is the facility that allows multiple operating systems to simultaneously share x86 processor resources in a safe and efficient manner, a facility generically known as hardware virtualization...
(formerly Vanderpool).
All Pentium D processors supported Intel 64 (formerly EM64T), XD Bit, and were manufactured for the LGA 775 form factor. The only motherboard
Motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
s guaranteed to work with the Pentium D (and Extreme Edition) branded CPUs were those based on the 945-, 955-, 965- and 975-series Intel chipsets, as well as the nForce 4 SLI Intel Edition
NForce4
The nForce4 is a motherboard chipset released by Nvidia in October, 2004. The chipset supports AMD 64-bit processors and Intel Pentium 4 LGA 775 processors.-nForce4/nForce4-4x:...
and ATI
ATI Technologies
ATI Technologies Inc. was a semiconductor technology corporation based in Markham, Ontario, Canada, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technologies Inc., the company was listed publicly in 1993 and was acquired by Advanced Micro...
Radeon Xpress
Xpress 200
The Radeon Xpress 200 is a computer chipset released by ATI. The chipset supports AMD 64-bit processors as well as supporting Intel Pentium 4, Pentium D and Celeron processors...
. The Pentium D 820 did not work with the nForce 4 SLI Intel Edition chipset due to some power design issues, though they were rectified in the X16 version. The 915- and 925-series chipsets did not work at all with the Smithfields, as they did not support more than one core (to prevent motherboard manufacturers from using them for Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
branded motherboards, as had happened with the 875P chipset). The 865- and 875-series chipsets supported multiprocessing. Motherboards with them might be Pentium D compatible with an updated BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
.
A week after its launch, Intel officially denied a report in Computerworld Today Australia that the Pentium D branded CPUs included "secret" digital rights management
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
features in their hardware that could be utilized by Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
and other operating systems, but was not publicly disclosed. While Intel admitted that there were some DRM technologies in the 945- and 955-series chipsets, it stated that the extent of the technologies was exaggerated, and that the technologies in question had been present in Intel's chipsets since the 875P.
Presler
The last generation of Pentium D branded processors was Presler identified by the product code 80553, and made of two 65 nm65 nanometer
The 65 nm process is an advanced lithographic node used in volume CMOS semiconductor fabrication. Printed linewidths can reach as low as 25 nm on a nominally 65 nm process, while the pitch between two lines may be greater than 130 nm.. For comparison, cellular ribosomes are...
-process cores found also in Pentium 4
Pentium 4
Pentium 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...
branded Cedar Mill CPUs. Presler introduced the 'multi-chip module, or MCM, which consisted of two single-core dies
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
placed next to each other on the same substrate package. This allowed Intel to produce these processors at a reduced production cost as a result of higher yields. Presler was supported by the same chipsets as Smithfield. It was produced using 65 nm
65 nanometer
The 65 nm process is an advanced lithographic node used in volume CMOS semiconductor fabrication. Printed linewidths can reach as low as 25 nm on a nominally 65 nm process, while the pitch between two lines may be greater than 130 nm.. For comparison, cellular ribosomes are...
technology similar to Yonah. Presler communicated with the system using an 800 MT/s FSB, and its two cores communicated also using the FSB, just as in Smithfield. Presler also included Intel VT-x (formerly Vanderpool) –although this was limited to the 9x0 models, and not in the 9x5 models– Intel 64, XD bit, and EIST (Enhanced Intel SpeedStep
SpeedStep
SpeedStep 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...
Technology). Presler was released in the first quarter of 2006 with a 2x2 MB Level 2 cache. Its models included 915, 920, 925, 930, 935, 940, 945, 950 and 960 (with a respective 2.8, 2.8, 3.0, 3,0, 3.2, 3.2, 3.4, 3.4, and 3.6 GHz clock frequency).
All steppings of Presler models 915, 920, 925, 930, and 935, as well as the C1, D0 steppings of 940, 945, and 950 and the 960 D0 stepping were rated at a 95 watt TDP
Thermal Design Power
The 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...
. All other models (i.e. certain models with 3.2 GHz or faster clock frequencies) were rated at 130 watt — a 37% increase in power consumption.
[*] The first batch of Presler processors (revision B1) had the EIST feature turned off by a microcode update because of stability issues. That affected only its power consumption, when idle, and thermal dissipation. Chips with working EIST started shipping in Q2 2006. They had a different S-Spec number which can be found in Intel errata documentation.
Smithfield XE
The Pentium Extreme Edition was introduced at the Spring 2005 Intel Developers Forum, not to be confused with the "Pentium 4 Extreme Edition" (an earlier, single-core processor occupying the same niche). The processor was based on the dual-core Pentium D branded Smithfield, but with Hyper-threadingHyper-threading
Hyper-threading is Intel's term for its simultaneous multithreading implementation in its Atom, Intel Core i3/i5/i7, Itanium, Pentium 4 and Xeon CPUs....
enabled, thus any operating system saw four logical processors (two physical and two virtual). It also had an unlocked multiplier to allow overclocking. It was initially released as Intel Pentium Extreme Edition 840 at 3.20 GHz, in early 2005, at a price point of $999.99 (OEM
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
price) or $1,200 (retail). The only chipsets that worked with the Extreme Edition 840 were Intel's 955X, NVIDIA's nForce4 SLI Intel Edition, and ATi Radeon Xpress 200. Using a Pentium Extreme Edition branded CPU with an Intel 945-series chipset will disable Hyper-threading effectively turning the processor into a Pentium D branded equivalent.
Presler XE
The Pentium Extreme Edition based on the dual-core Pentium D branded Presler was introduced as the 955 model, at 3.46 GHz, and used a 1066 MT/sMegatransfer
In computer technology, transfers per second and its more common derivatives gigatransfers per second and megatransfers per second are informal language that refer to the number of operations transferring data that occur in each second in some given data-transfer channel. It is also known as...
FSB compared to the 800 MT/s in the non-Extreme edition. A second version, the 965 at 3.73 GHz followed in March 2006. Both CPU's also feature Hyper-Threading Technology. Many overclockers, however, had been able to overclock the core to 4.26 GHz using air cooling simply by raising the unlocked CPU multiplier.
The 'Presler Extreme Edition' would run only combined with the Intel 975X chipset (it could also work with the 955X chipset, though this combination was not supported by Intel). The i975X featured the ICH7R southbridge
Southbridge (computing)
The southbridge is one of the two chips in the core logic chipset on a personal computer motherboard, the other being the northbridge. The southbridge typically implements the slower capabilities of the motherboard in a northbridge/southbridge chipset computer architecture. In Intel chipset...
and supported all LGA 775 (Socket T) Pentium 4, Pentium D, and Pentium Extreme Edition branded processors.
Successor
The Pentium D brand was succeeded on July 27, 2006 by the Core 2 branded line of microprocessorMicroprocessor
A 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 Core microarchitecture released as dual- and quad-core microprocessors branded Duo, Quad, and Extreme.
Implementation
In a single-processor scenario, the CPU-to-northbridgeNorthbridge (computing)
The northbridge has historically been one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Increasingly these functions have migrated to the CPU chip itself, beginning with memory and graphics controllers. For Intel Sandy Bridge and AMD Fusion...
link is point-to-point and the only real requirement is that it is fast enough to keep the CPU fed with data from memory
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
.
When assessing the Pentium D, it is important to note that it is essentially two CPUs in the same package and that it will face the same bus contention
Bus contention
Bus contention, in computer design, is an undesirable state of the bus in which more than one device on the bus attempts to place values on the bus at the same time. Most bus architectures require their devices follow an arbitration protocol carefully designed to make the likelihood of contention...
issues as a pair of Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
s prior to the Dual Independent Bus architecture introduced with the Dual-Core Dempsey Xeons. To use a crude analogy one could say that instead of using a single cable between CPU and north bridge, one must use a Y-splitter. Leaving aside advanced issues such as cache coherency
Cache coherency
In computing, cache coherence refers to the consistency of data stored in local caches of a shared resource.When clients in a system maintain caches of a common memory resource, problems may arise with inconsistent data. This is particularly true of CPUs in a multiprocessing system...
, each core can only use half of the 800 MT/s FSB bandwidth when under heavy load.
Comparison to Athlon 64 X2
The competing Athlon 64 X2, although running at lower clock rates and lacking Hyper-threadingHyper-threading
Hyper-threading is Intel's term for its simultaneous multithreading implementation in its Atom, Intel Core i3/i5/i7, Itanium, Pentium 4 and Xeon CPUs....
, had some significant advantages over the Pentium D, such as an integrated memory controller
Memory controller
The memory controller is a digital circuit which manages the flow of data going to and from the main memory. It can be a separate chip or integrated into another chip, such as on the die of a microprocessor...
, a high-speed HyperTransport
HyperTransport
HyperTransport , formerly known as Lightning Data Transport , is a technology for interconnection of computer processors. It is a bidirectional serial/parallel high-bandwidth, low-latency point-to-point link that was introduced on April 2, 2001...
bus, a shorter pipeline (12 stages compared to the Pentium D's 31), and better floating point
Floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
performance, more than offsetting the difference in raw clock speed. Also, while the Athlon 64 X2 inherited mature multi-core
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
control logic from the multi-core Opteron, the Pentium D was seemingly rushed to production and essentially consisted of two CPUs in the same package. Indeed, shortly after the launch of the mainstream Pentium D branded processors (26 May 2005) and the Athlon 64 X2 (31 May 2005), a consensus arose that AMD's implementation of multi-core
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
was superior to that of the Pentium D. As a result of this and other factors, AMD surpassed Intel in CPU sales at US retail stores for a period of time, although Intel retained overall market leadership because of its exclusive relationships with direct sellers such as Dell.
Comparison to Pentium Dual-Core
In 2007, Intel released a new line of desktop processors under the brand Pentium Dual Core, using the Core microarchitecture (which was based upon the Pentium MPentium M
The Pentium M brand refers to a family of mobile single-core x86 microprocessors introduced in March 2003 , and forming a part of the Intel Carmel notebook platform under the then new Centrino brand...
architecture, which was itself based upon the Pentium III
Pentium III
The 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...
). The newer Pentium Dual-Core processors give off considerably less heat (65 watt) than the Pentium D (95 or 130 watt). They also run at lower clock rates, only have up to 2 MB L2 Cache memory while the Pentium D has up to 2x2 MB, and they lack Hyper-threading. On the other hand, the Pentium Dual-Core has a wider execution unit (4 issues wide compared to the Pentium D's 3) and its 14 stages-long pipeline is less than half the length of the Pentium D's, allowing it to outperform the Pentium D in most applications.