Intel Core

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Intel Core is a brand name used for various mid-range to high-end consumer and business microprocessors. In general, processors sold as Core are more powerful variants of the same processors marketed as entry-level Celeron and Pentium. Similarly, identical or more capable versions of Core processors are also sold as Xeon processors for the server market.

The current lineup of Core processors includes the latest Intel Core i7 and Intel Core i5 and the older Intel Core 2 Solo, Intel Core 2 Duo, Intel Core 2 Quad and Intel Core 2 Extreme lines.

[edit] Overview

[edit] Yonah based

Core

Produced	From 2006 to 2008
Common manufacturer(s)	Intel
Max. CPU clock	1.06 GHz to 2.33 GHz
FSB speeds	533 MHz to 667 MHz
Min. feature size	65nm
Instruction set	x86-686
Microarchitecture	P6 microarchitecture
Cores	1 or 2
Socket(s)	Socket M
Core name(s)	Yonah

The original Core brand refers to Intel's 32-bit mobile dual-core x86 CPUs that derived from the Pentium M branded processors. The processor family used a more enhanced version of the Intel P6 microarchitecture. It emerged in parallel with the NetBurst (Intel P68) microarchitecture of the Pentium 4 brand, and was a precursor of the 64-bit Core microarchitecture of Core 2 branded CPUs. The Core brand comprised two branches: the Duo (dual-core) and Solo (Duo with one disabled core, which replaced the Pentium M brand of single-core mobile processor).

The Core brand was launched on January 5, 2006 by the release of the 32-bit Yonah CPU - Intel's first dual-core mobile (low-power) processor. Its dual-core layout closely resembled two interconnected Pentium M branded CPUs packaged as a single die (piece) silicon chip (IC). Hence, the 32-bit microarchitecture of Core branded CPUs - contrary to its name - had more in common with Pentium M branded CPUs than with the subsequent 64-bit Core microarchitecture of Core 2 branded CPUs. Despite a major rebranding effort by Intel starting January 2006, some computers with the Yonah core continued to be marked as Pentium M.

The Core series is also known for being the first Intel processor to be used as the main CPU for an Apple Macintosh computer. The Core Duo was the CPU for the first generation Macbook Pro while the Core Solo appeared in Apple's Mac Mini line. Core Duo signified the beginning of Apple's shift to Intel processors across their entire line.

In 2007, Intel began branding the Yonah core CPUs intended for mainstream mobile computers as Pentium Dual-Core. These are not to be confused with the desktop 64-bit Core microarchitecture CPUs also branded as Pentium Dual-Core.

September 2007 and January 4, 2008 mark a discontinuation of many Core branded CPUs.^[1][2]

[edit] Core Duo

Intel Core Duo (product code 80539) consists of two cores on one die, a 2 MB 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. These processors are CISC.

[edit] Core Solo

Intel Core Solo (product code 80538) 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^{[citation needed]}. 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] 64-bit Core microarchitecture based

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 small form factor and all-in-one desktops, like the iMac and the Mac Mini, also used Core processors).

Unlike the Intel Core, Intel Core 2 is a 64-bit processor, supporting Intel 64. Another difference 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 tripled the amount of on-board cache to 6 MB. Core 2 also introduced a quad-core performance variant to the single- and dual-core chips, branded Core 2 Quad, as well as an enthusiast variant, Core 2 Extreme. All three chips are manufactured at a 65 nm lithiography, and in 2008, a 45 nm lithiography and support Front Side Bus speeds ranging from 533 MHz to 1600 MHz. In addition, the 45 nm die shrink of the Core microarchitecture adds SSE4.1 support to all Core 2 microprocessors manufactured at a 45 nm lithiography, therefore increasing the calculation rate of the processors.

[edit] Core 2 Solo

The Core 2 Solo, introduced in September 2007, is the successor to the Core Solo and is available only as an ultra-low-power mobile processor with 5.5 Watt thermal design power. The original U2xxx series "Merom-L" was using a special version of the Merom chip with CPUID number 10661 (model 22, stepping A1) that only had a single core and was also used in some Celeron processors. The later SU3xxx are part of Intel's CULV range of processors in a smaller µFC-BGA 956 package but contain the same Penryn chip as the dual-core variants, with one of the cores disabled during manufacturing.

[edit] Core 2 Duo

The majority of the desktop and mobile Core 2 processor variants are Core 2 Duo with two processor cores on a single Merom, Conroe, Allendale, Penryn or Wolfdale chip. These come in a wide range of performance and power consumption, starting with the relatively slow ultra-low-power Uxxxx (10 W) and low-power Lxxxx (17 W) versions, to the more performance oriented Pxxxx (25 W) and Txxxx (35 W) mobile versions and the Exxxx (65 W) desktop models. The mobile Core 2 Duo processors with an 'S' prefix in the name are produced in a smaller µFC-BGA 956 package which allows building more compact Laptops.

Within each line, a higher number usually refers to a better performance, which depends largely on core and front-side bus clock frequence and amount of second level cache, which are model specific. Core 2 Duo processors typically use the full L2 cache of 2, 3, 4 or 6 MB available in the specific stepping of the chip, while versions with the amount of cache reduced during manufacturing are sold for the low-end consumer market as Celeron or Pentium Dual-Core Dual-Core processors. Like those processors, some low-end Core 2 Duo models disable features such as Intel Virtualization Technology. Details can be found at the list of Intel Core 2 microprocessors.

[edit] Core 2 Quad

Core 2 Quad processors are multi-chip modules consisting of two dies similar to those used in Core 2 Duo, forming a quad-core processor. While this allows twice the performance to a dual-core processors at the same clock frequency in ideal conditions, this is highly workload specific and requires applications to take advantage of the extra cores. Also, high-end Core 2 Duo processors often operate at higher clock frequencies, so the performance for single-thread workloads would be worse on a Core 2 Quad.

Initially, all Core 2 Quad models were versions of Core 2 Duo desktop processors, Kentsfield derived from Conroe and Yorkfield from Wolfdale, but later Penryn-QC was added as a high-end version of the mobile dual-core Penryn.

The Xeon 31xx and 33xx processors are mostly identical versions of the desktop Core 2 Quad processors and can be used interchangeably.

[edit] Core 2 Extreme

Core 2 Extreme processors are enthusiast versions of Core 2 Duo and Core 2 Quad processors, usually with a higher clock frequency and an unlocked clock multiplier, which makes them especially attractive for overclocking. This is similar to earlier Pentium processors labeled as Extreme Edition. Core 2 Extreme processors were released at a much higher price than their regular version, often $999 or more.

[edit] Nehalem microarchitecture based

With the Nehalem microarchitecture, Intel introduced a new naming scheme for its Core processors. As before, there are four variants, now Core i3, Core i5, Core i7 and Core i9, but the names no longer corresponds to specific technical features like the number of cores. Instead, the brand is now divided from mid-range (i3) to high-end (i7, i9)^[3]. As of September 2009, only Core i5 and Core i7 processors have been released, while Core i3 and Core i9 have been shown at the Intel Developer Forum and announced by Intel^[4]. Common features of all Nehalem based processors include an integrated DDR3 memory controller as well as QuickPath Interconnect or PCI Express and Direct Media Interface on the processor replacing the aging quad-pumped Front Side Bus used in all earlier Core processors. Also, all these processors have 256 KB L2 cache per core, plus up to 12 MB shared level 3 cache. Because of the new I/O interconnect, chipsets and mainboards from previous generations can no longer be used with Nehalem based processors.

[edit] Core i3

When the Core 2 brand is phased out in 2010's 3rd quarter, it is expected to be succeeded by the Core i3 along with the already released Core i5 and Core i7 processors. The first Nehalem based Core i3 was announced to be Clarkdale with an integrated GPU and two cores^[5]. The same processor will also be available as Core i5 and Pentium, with slightly different configurations.

The Core i3-3xxM processors have been announced to be based on Arrandale, the mobile version of the Clarkdale desktop processor. They will be similar to the Core i5-4xx series but running at lower clock speeds and without Turbo Boost.^[6]

According to some sources, existing Core 2 processors based on Yorkfield, Wolfdale and Penryn may also get rebranded to Core i3^[7].

[edit] Core i5

Core i5, like Core i7, is based on the Nehalem microarchitecture. The first Core i5 was introduced on September 8, 2009 and is a mainstream variant of the Core i7, initially only quad-core desktop processors based on Lynnfield, with dual-core mobile (Arrandale) and desktop processors (Clarkdale) following in 2010.

[edit] Core i7

As of 2009, Core i7 is the high end of the Core brand, which was introduced with the Bloomfield Quad-core processor in late 2008. In 2009, new Core i7 models based on the cheaper Lynnfield desktop quad-core processor and the Clarksfield quad-core mobile were added, and models based on the Arrandale dual-core mobile processor have been announced.

[edit] Core i9

The final addition^{[citation needed]} to the Nehalem based Core processor lineup will be the Core i9 brand in 2009, with the Gulftown six-core processor^[8]. Gulftown uses the same socket as Bloomfield, so Core i9 can be seen as an upgrade to the Core i7-9xx series.

[edit] See also

Computer Science portal

• Centrino
• Pentium (disambiguation)
• Xeon
• Celeron
• List of Intel Core microprocessors

[edit] External links

• 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

[edit] References