Intel Core
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This article is about Intel processors branded as "Intel Core", such as the 65 nanometre processor codenamed Yonah and its variants. For the "Intel Core Microarchitecture" used in newer Intel microprocessors, see Intel Core microarchitecture. For Intel processors branded as "Intel Core 2", see Intel Core 2.
| Core Central processing unit |
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| Produced: | 2006 - |
| Manufacturer: | Intel |
| CPU Speeds: | 1.06 GHz to 2.33 GHz |
| FSB Speeds: | 533 MT/s to 667 MT/s |
| Process: (MOSFET channel length) |
0.065 µm |
| Instruction Set: | x86 |
| Microarchitecture: | P6 (Pentium M variant) |
| Socket: | Socket M |
| Core Name: | Yonah |
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Intel Core is the name used for the processor codenamed Yonah (Hebrew transliteration for Jonah - יונה), released on January 5, 2006. It replaced the Pentium M brand used for earlier mobile processors with the same microarchitecture. It was part of a major rebranding effort by Intel starting January 2006; the next generation of desktop and mobile processors after the Intel Core processor is the Intel Core 2, replacing the Pentium brand.
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[edit] Yonah
Yonah was the code name for Intel's first generation of 65 nm process mobile microprocessors, based on the Banias/Dothan Pentium M microarchitecture, incorporating LaGrande security technology. 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.
Core Duo is the world's first low-power (less than 25 watts) Dual Core microprocessor, with the previous low being AMD's 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 is 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).[citation needed]
Contrary to early reports, the Intel Core Duo supports Intel's Vanderpool x86 virtualization technology, 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). However, it seems some vendors have chosen to disable this feature by default[citation needed], making it available through a BIOS option[citation needed].
EM64T (Intel's version of x86-64) is not supported by Yonah. However, EM64T support is integrated in Yonah's successor, the mobile version of Core 2, code-named Merom.
Intel Core Duo consists of two cores on one die, a 2 MiB L2 cache shared by both cores, and an arbiter bus that controls both L2 cache and FSB access. Upcoming steppings of Core Duo processors will also include the ability to disable one core to conserve power.
Intel Core Solo uses the same two-core die as the Core Duo, but features only one active core. This allows Intel to sell dies that have a manufacturing defect in one but not both of the cores. Depending on demand, Intel may also simply disable one of the cores to sell the chip at the Core Solo price -- this requires less effort than launching and maintaining a separate line of CPUs that physically only have one core. Intel used the same strategy previously with the 486 CPU in which early 486SX CPUs were in fact manufactured as 486DX CPUs but the FPU failed quality control and the connection was physically severed.
[edit] Technical specifications
Core Duo contains 151 million transistors, including the shared 2 MiB L2 cache. Yonah's execution core contains a 12 stage pipeline, forecasted to eventually be able to clock at 2.33–2.50 GHz of maximum frequency. The communication between the L2 cache and both execution cores is handled by an arbitration bus unit, 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.
Yonah is supported by the 945GM, 945PM, 945GT, 965GM, 965PM, and 965GT system chipsets. Core Duo and Core Solo use Socket M. 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 Virtualization Technology. Early Intel specifications mistakenly claimed a halving of the Thermal Design Power.
New T2150 & T2250 have also appeared in OEM systems as a low-cost option with a lower 533Mhz FSB and no Virtualization Technology. No official data on these processors is yet available from Intel.
[edit] Advantages and shortcomings
In many categories of performance (which support both cores), Yonah represents an uncharacteristically large improvement over its immediate predecessor:
- two computational cores with no significant increase in power consumption
The shortcomings of Yonah are largely inherited from previous Pentium M architectures:
- high memory latency due to the lack of on-die memory controller (further aggravated by system-chipset's use of DDR-II RAM)
- poor Floating Point Unit (FPU) throughput due to the smaller number of FP units in each CPU core.
- no 64-bit (EM64T) support
- same or even slightly worse "performance per watt" in single threaded applications compared to its predecessor.
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. This is a weakness shared by the entire line of Pentium processors (desktop, server, and mobile.) However, application tests show that Yonah's L2-cache system is quite effective at hiding main-memory latency from the execution core, thus diminishing the impact of that latency on real-life performance.
Many feel that Yonah's lack of 64-bit support will be a significant limitation in the future. However, support for 64-bit operating systems is currently limited in the consumer retail market (the only available consumer retail fully-64-bit operating systems include Windows XP 64-bit Edition and some Linux distributions), a situation unlikely to change until the releases of Windows Vista and Mac OS X v10.5 in 2006-2007. Also, few laptops support more than 2 GB of RAM, negating the 64-bit's large physical address space capability. Hence, for its intended market (mobile and laptop PCs) the lack of EM64T appeared inconsequential at the time Yonah was released.
The Sossaman processor for servers, which is based on Yonah, also lacks EM64T support. For the server market, this has more severe consequences, since all major server operating systems already support EM64T, and the upcoming Exchange 12 even requires a 64-bit processor to run.
According to Mobile Roadmaps from 2005, Intel originally seems to have focused more on the power consumption of its p6+ Pentium M and Core processors and aimed to reduce it by 50% with Yonah. Intel originally planned to continue offering desktop (NetBurst) derivations with reduced power consumption for mobile performance solutions and only use p6+ Pentium M/Core processors as medium-to-low performance, low power consumption parts. The policy was apparently changed later on to trying to keep the power consumption more or less at the same level and increasing the performance by as much as possible. This change in policy probably resulted from Intel's changed policy of abandoning NetBurst and replacing it with p6+ Pentium M/Core. This meant a shift in priority of the p6+ Pentium M/Core more towards high performance and less towards low power consumption.
According to Intel's product roadmap, the 64-bit Intel Core 2 is scheduled to replace the Intel Core. By 2Q 2007, Intel expects 90% of its laptop CPU production will be based on the Core 2 architecture. For a product of such architectural and market significance, Core will have had an unusually short lifespan.
[edit] Sossaman
A derivative of Yonah, code-named Sossaman, was released on 14 March 2006 as the Dual-Core Xeon LV. Sossaman is virtually identical to Yonah, except that Sossaman supports dual-socket configurations (for a total of 4 cores) and implements 36-bit memory addressing (PAE mode).
[edit] Successor
The successor to Core is the mobile version of the Intel Core 2 line of processors using cores based upon the Intel Core microarchitecture, released on July 27, 2006. The release of the mobile version of Intel Core 2 marks the reunification of Intel's desktop and mobile product lines as Core 2 processors were released for desktops and notebooks, unlike the first Intel Core CPUs that were targeted only for notebooks (although some desktop models of Macintosh, such as the first Intel-based iMac and Mac mini, used the Core Duo).
Unlike the Intel Core, Intel Core 2 is a 64-bit processor, supporting EM64T.
Other than another bump in the processor speed, one of the primary differences between the original Core Duo and the new Core 2 Duo is an increase in the amount of Level 2 cache. The new Core 2 Duo has doubled the amount of on-board cache to 4MB. Both chips have a 65-nm process technology architecture and support a 667-1066 MHz front-side-bus (FSB).
[edit] See also
List of Intel Core microprocessors
[edit] 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
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