Intel Core
Encyclopedia
Yonah was the code name for (the core of) 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 performance decreased slightly due to higher latency cache. Additionally, Yonah includes support for the NX bit
.
Duo brand refers to a low-power (less than 25 watts) dual-core microprocessor, which offered lower power operation than the competing AMD Opteron
260 and 860 HE at 55 watts. Core Duo was released on 5 January 2006, with the other components of the Napa platform. It was the first Intel processor to be used in Apple Macintosh products (although the Apple Developer Transition Kit machines, non-production units distributed to some developers, used Pentium 4
processors).
Contrary to early reports, the Intel Core Duo supports Intel VT-x x86 virtualization
, except in the T2300E model and proprietary T2050/T2150/T2250 mounted by OEMs (cf. the Intel Centrino Duo Mobile Technology Performance Brief and Intel's Processor Number Feature Table). The Intel Pentium Dual Core processors do not have this feature. However some vendors (including HP) chose to disable this feature, with others making it available through a BIOS option.
There were two variants and one derivative of the Yonah, which did not bear the "Intel Core" brand name. A dual-core (server) derivative, code-named Sossaman, was released on 14 March 2006 as the Xeon
(branded) LV (low-voltage). The Sossaman differed from the Yonah only in its support for dual-socket configurations (two CPUs - i.e. four cores - on board, like AMD Quad FX), and implementation of 36-bit memory addressing (PAE
mode). A single-core variant, code-named Yonah-1024, was released as the Celeron
(branded) M 400 series CPUs. It was largely identical to the Core Solo branded Yonah, except that it only had half the L2 cache and did not support SpeedStep
and Intel VT-x. Another dual-core variant of the Core Duo branded Yonah was released as the Intel Pentium Dual-Core
branded T2060, T2080, and T2130 mobile CPUs, also without Intel VT-x support.
Intel 64 (Intel's x86-64
implementation) is not supported by Yonah. However, Intel 64 support is integrated in Yonah's successor, the mobile version of Core 2
, code-named Merom
.
s, including the shared 2 MiB
L2 cache. Yonah's execution core contains a 12 stage pipeline, forecast to eventually be able to run at a maximum frequency of 2.33–2.50 GHz. The communication between the L2 cache and both execution cores is handled by a bus unit controller through arbitration, which reduces cache coherency traffic over the FSB
, at the expense of raising the core-to-L2 latency from 10 clock cycles (in the Dothan Pentium M) to 14 clock cycles. The increase in clock frequency offsets the impact of the increased clock cycle latency. The power management components of the core features improved grained thermal control, as well as independent scaling of power between the two cores, resulting in very efficient management of power.
Core processors communicate with the system chipset over a 667 MT/s front side bus
(FSB), up from 533 MT/s used by the fastest Pentium M.
T2050 & T2250 have also appeared in OEM systems as a low-cost option with a lower 533 MHz FSB and no Intel VT-x.
Yonah is supported by the 945GM, 945PM, 945GT, 965GM, 965PM, and 965GT system chipsets. Core Duo and Core Solo use Socket M
, but due to pin arrangement and new chipset functions are not compatible with any previous Pentium M
motherboard.
The T2300E was later introduced as a replacement for the T2300. It has dropped support for Intel VT-x. Early Intel specifications mistakenly claimed a halving of the Thermal Design Power
.
The shortcomings of Intel Core (Yonah) are:
The Yonah platform requires all main-memory transactions to pass through the Northbridge
of the chipset, increasing latency compared to the AMD's Turion platform. However, application tests showed Intel Core's L2-cache system is quite effective at overcoming main-memory latency; despite this limitation, Intel Core (Yonah) sometimes managed to outperform AMD's Turion.
The Sossaman processor for servers, which is based on Yonah, also lacks Intel 64-bit support. For the server market, this had severe consequences, since all major server operating systems already supported x86-64, and Microsoft Exchange Server
2007 requires a 64-bit processor to run.
According to Mobile Roadmaps from 2005, Intel's Yonah project originally focused more on reducing the power consumption of its P6-based Pentium M processor and aimed to reduce it by 50% for Intel Core (Yonah). Intel continued recommending the NetBurst-based Mobile Pentium 4 processors for high performance applications (although these were less power efficient and gave off significantly more heat) until the Yonah project succeeded in extracting higher performance from its lower-power-consumption design. The Intel Core Duo's inclusion of two highly-efficient cores on one chip can provide better performance than a Mobile Pentium 4 core, but with much better power-efficiency. Intel no longer recommends its Mobile Pentium 4 processors for mobile devices as they are outdated.
On July 27, 2006, Intel's Core 2 processors were released. By Q2 2007, Intel expected 90% of its laptop CPU production to be converted to the heavily-revised Intel Core 2 processors. The original Intel Core (Yonah) product had an unusually short lifespan as a stepping stone to the 64-bit Intel Core 2.
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...
's first generation of 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...
process mobile microprocessors, based on the Banias/Dothan-core Pentium M microarchitecture. SIMD
SIMD
Single instruction, multiple data , is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data simultaneously...
performance has been improved through the addition of SSE3
SSE3
SSE3, Streaming SIMD Extensions 3, also known by its Intel code name Prescott New Instructions , is the third iteration of the SSE instruction set for the IA-32 architecture. Intel introduced SSE3 in early 2004 with the Prescott revision of their Pentium 4 CPU...
instructions and improvements to SSE
Streaming SIMD Extensions
In computing, Streaming SIMD Extensions is a SIMD instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series processors as a reply to AMD's 3DNow! . SSE contains 70 new instructions, most of which work on single precision floating point...
and SSE2
SSE2
SSE2, 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...
implementations, while integer performance decreased slightly due to higher latency cache. Additionally, Yonah includes support for the NX bit
NX bit
The 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...
.
Brand names
The Intel CoreIntel Core
Yonah 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...
Duo brand refers to a low-power (less than 25 watts) dual-core microprocessor, which offered lower power operation than the competing AMD Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
260 and 860 HE at 55 watts. Core Duo was released on 5 January 2006, with the other components of the Napa platform. It was the first Intel processor to be used in Apple Macintosh products (although the Apple Developer Transition Kit machines, non-production units distributed to some developers, used 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...
processors).
Contrary to early reports, the Intel Core Duo supports Intel VT-x 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...
, except in the T2300E model and proprietary T2050/T2150/T2250 mounted by OEMs (cf. the Intel Centrino Duo Mobile Technology Performance Brief and Intel's Processor Number Feature Table). The Intel Pentium Dual Core processors do not have this feature. However some vendors (including HP) chose to disable this feature, with others making it available through a BIOS option.
There were two variants and one derivative of the Yonah, which did not bear the "Intel Core" brand name. A dual-core (server) derivative, code-named Sossaman, was released on 14 March 2006 as the 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) LV (low-voltage). The Sossaman differed from the Yonah only in its support for dual-socket configurations (two CPUs - i.e. four cores - on board, like AMD Quad FX), and implementation of 36-bit memory addressing (PAE
Physical Address Extension
In computing, Physical Address Extension is a feature to allow x86 processors to access a physical address space larger than 4 gigabytes....
mode). A single-core variant, code-named Yonah-1024, was released as the Celeron
Celeron
Celeron is a brand name given by Intel Corp. to a number of different x86 computer microprocessor models targeted at budget personal computers....
(branded) M 400 series CPUs. It was largely identical to the Core Solo branded Yonah, except that it only had half the L2 cache and did not support 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...
and Intel VT-x. Another dual-core variant of the Core Duo branded Yonah was released as the Intel Pentium Dual-Core
Intel Pentium Dual-Core
The Pentium Dual-Core brand was used for mainstream x86-architecture microprocessors from Intel from 2006 to 2009 when it was renamed to Pentium...
branded T2060, T2080, and T2130 mobile CPUs, also without Intel VT-x support.
Intel 64 (Intel's 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...
implementation) is not supported by Yonah. However, Intel 64 support is integrated in Yonah's successor, the mobile version of Core 2
Intel Core 2
Core 2 is a brand encompassing a range of Intel's consumer 64-bit x86-64 single-, dual-, and quad-core microprocessors based on the Core microarchitecture. The single- and dual-core models are single-die, whereas the quad-core models comprise two dies, each containing two cores, packaged in a...
, code-named Merom
Merom (microprocessor)
Merom is the code name for various Intel processors that are sold as Core 2 Duo, Core 2 Solo, Pentium Dual-Core and Celeron. It was the first mobile processor to be based on the Core microarchitecture, replacing the Enhanced Pentium M based Yonah processor. Merom has product code 80537, which is...
.
| Brand (main article) | Model (list) | Cores | L2 Cache | 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... |
|---|---|---|---|---|
| Core Duo | T2xxx | 2 | 2 MiB | 31 W |
| L2xxx | 15 W | |||
| U2xxx | 9 W | |||
| Core Solo | T1xxx | 1 | 2 MiB | 27-31 W |
| U1xxx | 5.5-6 W | |||
| Pentium Dual-Core | T2xxx | 2 | 1 MiB | 31 W |
| Celeron Celeron Celeron is a brand name given by Intel Corp. to a number of different x86 computer microprocessor models targeted at budget personal computers.... |
M 215 | 1 | 512 KB | 27 W |
| M 4x0 | 1 MiB | 27 W | ||
| M 4x3 | 5.5 W |
Technical specifications
Core Duo contains 151 million transistorTransistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s, including the shared 2 MiB
Mebibyte
The mebibyte is a multiple of the unit byte for digital information. The binary prefix mebi means 220, therefore 1 mebibyte is . The unit symbol for the mebibyte is MiB. The unit was established by the International Electrotechnical Commission in 2000 and has been accepted for use by all major...
L2 cache. Yonah's execution core contains a 12 stage pipeline, forecast to eventually be able to run at a maximum frequency of 2.33–2.50 GHz. The communication between the L2 cache and both execution cores is handled by a bus unit controller through arbitration, which reduces cache coherency traffic over the FSB
Front side bus
A 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....
, at the expense of raising the core-to-L2 latency from 10 clock cycles (in the Dothan Pentium M) to 14 clock cycles. The increase in clock frequency offsets the impact of the increased clock cycle latency. The power management components of the core features improved grained thermal control, as well as independent scaling of power between the two cores, resulting in very efficient management of power.
Core processors communicate with the system chipset over a 667 MT/s front side bus
Front side bus
A 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....
(FSB), up from 533 MT/s used by the fastest Pentium M.
T2050 & T2250 have also appeared in OEM systems as a low-cost option with a lower 533 MHz FSB and no Intel VT-x.
Yonah is supported by the 945GM, 945PM, 945GT, 965GM, 965PM, and 965GT system chipsets. Core Duo and Core Solo use Socket M
Socket M
Socket M is a CPU interface introduced by Intel in 2006 for the Intel Core line of mobile processors.-Technical specifications:Socket M is used in all Intel Core products, as well as the Core-derived Dual-Core Xeon codenamed Sossaman...
, but due to pin arrangement and new chipset functions are not compatible with any previous Pentium M
Pentium 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...
motherboard.
The T2300E was later introduced as a replacement for the T2300. It has dropped support for Intel VT-x. Early Intel specifications mistakenly claimed a halving of the 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...
.
Advantages and shortcomings
The Duo version of Intel Core (Yonah) includes two computational cores, providing performance per watt almost as good as any previous single core Intel processors. In battery-operated devices such as notebook computers, this translates to getting as much total work done per battery charge as with older computers, although the same total work may be done faster. When parallel computations and multiprocessing are able to utilize both cores, the Intel Core Duo delivers much higher peak speed compared to the single-core chips previously available for mobile devices.The shortcomings of Intel Core (Yonah) are:
- The same or even slightly worse performance per watt in single threaded or non-parallel applications compared to its predecessor.
- 32-bit processes only. 64-bit64-bit64-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...
processes are not supported. (See the Intel Core 2Intel Core 2Core 2 is a brand encompassing a range of Intel's consumer 64-bit x86-64 single-, dual-, and quad-core microprocessors based on the Core microarchitecture. The single- and dual-core models are single-die, whereas the quad-core models comprise two dies, each containing two cores, packaged in a...
successor, which is a 64-bit processor.) - High memory latency due to the lack of on-die memory controller (further aggravated by system-chipset's use of DDR2 SDRAMDDR2 SDRAMDDR2 SDRAM is a double data rate synchronous dynamic random-access memory interface. It supersedes the original DDR SDRAM specification and has itself been superseded by DDR3 SDRAM...
) - Limited Floating Point UnitFloating point unitA floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
(multiply/divide) throughput for non-parallel computations or single-threaded processes; this is due to the smaller number of floating-point units in each CPU core compared to some previous designs.
The Yonah platform requires all main-memory transactions to pass through the Northbridge
Northbridge (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...
of the chipset, increasing latency compared to the AMD's Turion platform. However, application tests showed Intel Core's L2-cache system is quite effective at overcoming main-memory latency; despite this limitation, Intel Core (Yonah) sometimes managed to outperform AMD's Turion.
The Sossaman processor for servers, which is based on Yonah, also lacks Intel 64-bit support. For the server market, this had severe consequences, since all major server operating systems already supported x86-64, and Microsoft Exchange Server
Microsoft Exchange Server
Microsoft Exchange Server is the server side of a client–server, collaborative application product developed by Microsoft. It is part of the Microsoft Servers line of server products and is used by enterprises using Microsoft infrastructure products...
2007 requires a 64-bit processor to run.
According to Mobile Roadmaps from 2005, Intel's Yonah project originally focused more on reducing the power consumption of its P6-based Pentium M processor and aimed to reduce it by 50% for Intel Core (Yonah). Intel continued recommending the NetBurst-based Mobile Pentium 4 processors for high performance applications (although these were less power efficient and gave off significantly more heat) until the Yonah project succeeded in extracting higher performance from its lower-power-consumption design. The Intel Core Duo's inclusion of two highly-efficient cores on one chip can provide better performance than a Mobile Pentium 4 core, but with much better power-efficiency. Intel no longer recommends its Mobile Pentium 4 processors for mobile devices as they are outdated.
On July 27, 2006, Intel's Core 2 processors were released. By Q2 2007, Intel expected 90% of its laptop CPU production to be converted to the heavily-revised Intel Core 2 processors. The original Intel Core (Yonah) product had an unusually short lifespan as a stepping stone to the 64-bit Intel Core 2.
See also
- Intel CoreIntel 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...
- MeromMerom (microprocessor)Merom is the code name for various Intel processors that are sold as Core 2 Duo, Core 2 Solo, Pentium Dual-Core and Celeron. It was the first mobile processor to be based on the Core microarchitecture, replacing the Enhanced Pentium M based Yonah processor. Merom has product code 80537, which is...
- CentrinoCentrinoThe 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 Core microprocessors
External links
- Intel Core Duo Web page
- Intel Core Solo Web page
- Processor comparison table
- Intel Core technical specifications
- techPowerUp! CPU Database
- Tested against AMD's 64 X2 line and Intel's own Pentium M
- Intel Centrino Duo Mobile Technology papers