Intel Core 2

Core 2 Duo brand logo

Core 2 Extreme brand logo

This article is about Intel processors branded as "Intel Core 2". For more information on the microarchitecture used in Intel Core 2 microprocessors, see Intel Core microarchitecture.

Core 2 is a ninth-generation x86 architecture microprocessor produced by Intel based on an all-new CPU architecture called the Intel Core microarchitecture, which is the successor of NetBurst microarchitecture that has powered most Intel processors since 2000. Core 2 also marks the retirement of Intel's Pentium brand name that has been used from 1993 and the reunion of Intel's notebook and desktop product lines since Pentium M was released apart from Pentium 4 in 2003.

The first wave of Core 2 processors was officially released on July 27, 2006. Like the Intel Core processors that they supersede, the Core 2 brand is subdivided into Duo (dual-core) and Extreme (high-end) models, with a possible Solo (single-core), and confirmed Quadro (quad-core) model on the way. The first generation of Core 2 products all have been dual core, with future plans for single and quad core varieties.

Unlike NetBurst-based processors, such as the Pentium 4 and Pentium D, Core 2 does not stress designs based on extremely high clock speeds but rather improvements on other CPU features, including cache efficiency and number of cores. The power consumption of these processors is much lower than the Pentium desktop line of products. With a TDP of only 65 W, Core 2 has the lowest power consumption of any desktop chip this generation, including both (Intel code named processor known as) Prescott's TDP of 130 W and (AMD codenamed processor known as) San Diego's TDP of 89 W.

Intel Core 2 processors feature EM64T (an implementation of AMD64), Virtualization Technology, Execute Disable Bit, and SSSE3. The release also introduced LaGrande Technology, Enhanced SpeedStep Technology, and Active Management Technology (iAMT2).

Current processor cores

Conroe

Intel Core 2 Duo E6600 "Conroe"

The first Intel Core 2 Duo processor cores, codenamed Conroe and "Allendale", were launched on 27 July 2006. These processors are built on a 65 nm process and are intended for desktops, replacing the Pentium 4 and Pentium D. Intel has claimed that Conroe provides 40% more performance at 40% less power compared to the Pentium D. Allendale and Conroe Core 2 Duo processors differ in the size of their L2 cache. Allendale contains 2 MB L2 cache, while Conroe has 4 MB L2 cache.

The Conroe processors are labeled as the E6600 and E6700 Core 2 Duo models, with the E6600 clocked at 2.4 GHz and the E6700 clocked at 2.67 GHz. The family has a 1066 MT/s front side bus, 4 MB shared L2 cache, and 65 watts TDP. These processors have been tested against AMD's current top performing processors, which were, until this latest Intel release, the fastest CPUs available, and the vanilla Conroe boasts much faster performance. Overclocking results show that the E6700 and E6600 are stable when overclocked to 4 GHz, despite having locked multipliers.

At launch time, Intel's prices for the Core 2 Duo E6600 and E6700 processors were $316 USD and $530 USD each in quantities of 1000.

Conroe XE

The top-of-the-line Core 2 Extreme was officially released on July 29 2006. However some retailers appear to have released it on July 13 2006, albeit at a high premium. The less powerful E6x00 models of Core 2 Duo were scheduled for simultaneous release with the X6800, which are both available at this time, though in limited quantities. It is powered by the Conroe XE core and replaces the Pentium 4 Extreme Edition and the dual-core Pentium Extreme Edition processors. Core 2 Extreme has a clock speed of 2.93 GHz and a 1066 MT/s FSB, although it was initially expected to achieve 3.33 GHz and 1333 MT/s. The TDP for this family is 75-80 watts. At full load the X6800 does not exceed 45 °C (113 °F), and with SpeedStep enabled the average temperature of the CPU when idle is 25 °C.

At launch time, Intel's price for the Core 2 Extreme X6800 was $999 USD each in quantities of 1000. Like the desktop Core 2 Duo, it has 4 MB of shared L2 cache available. This means that the only major difference between the regular Core 2 Duo and Core 2 Extreme is the clock speed, which is unusual for the "Extreme Edition." It does come with an unlocked multiplier, however, allowing it to basically simulate any E6x00 with 4 MB of L2 cache. This also allows it to gain a better overclocking ability than the other Core 2 processors, with up to a 14X multiplier. Intel's previous Extreme Editions all included a unique feature, such as an increased FSB, more L2 cache, or addition of L3 cache.

Benchmarking tests in multimedia and gaming have shown that the X6800 can lead the best AMD processor by up to 40% in performance. Overclocking proves more promising, as Intel allows the user to change the multiplier number. The X6800 has shown the ability to be overclocked to 3.4 GHz on Intel's stock cooler with no increase in voltage to the system components.

Allendale

Intel Core 2 Duo E6300 "Allendale"

Allendale is a codename for stripped down versions of the Conroe processors with only 2 MB of L2 cache. The E6300 (1.86 GHz) and E6400 (2.13 GHz), both with a 1066MT/s FSB, were released on July 27 2006. Traditionally, CPUs of the same family with less cache simply have the unavailable cache disabled (this allows parts that fail quality control to be sold at a lower rating), but this is not the case with Allendale. Allendale actually has a smaller die, which results in less heat production and a higher overclock. Some Allendale CPUs have been shown to overclock better than Conroe CPUs because of the smaller die size and lower temperatures. At launch time, Intel's prices for the Core 2 Duo E6300 and E6400 processors were $183 USD and $224 USD each in quantities of 1000. Allendale CPUs have an enormous value with their overclocking capabilities, the 1.86 GHz model has been shown to overclock to over 3.0 GHz with a good motherboard supporting high FSB speeds. In these reports, an overclocked Allendale 1.86 GHz was shown to edge out the Core 2 Extreme in certain benchmarks. According to well respected [reviews][1], the Allendale only suffers on average 3.5% because of the smaller L2 cache size. With the higher overclock of the Allendale, enthusiasts can easily make up the 3.5% percent by overclocking further than its Conroe cousin. However, the low multiplier on Allendale chips requires a very high FSB to reach high speeds, which few motherboards support.

Merom

Merom, the first mobile version of the Core 2, was officially released on July 27, 2006 but quietly began shipping to PC manufacturers in mid-July alongside Conroe. Merom is Intel's premier line of mobile processors, with largely the same features as Conroe but with more emphasis on low power consumption to enhance notebook battery life. Intel has claimed that Merom will provide 20% more performance yet maintain the same battery life as the Yonah-based Core Duo. Merom will be the first Intel mobile processor to feature EM64T 64-bit extensions.

Intel has stated that the first version of Merom is drop-in compatible with the current Core Duo platform, requiring at most a BIOS update. It has the same thermal envelope and the same 667 MT/s bus rate.

The Merom processors are labeled as the "T5x00" and "T7x00" Core 2 Duo models, with the T5500 clocked at 1.66 GHz, the T5600 clocked at 1.83 GHz, the T7200 clocked at 2.0 GHz, the T7400 clocked at 2.16 GHz, and the T7600 clocked at 2.33 GHz. The T5x00 models come with 2 MB of shared L2 cache, and the T7x00 models come with 4 MB of shared L2 cache.

See Also

List of laptops using Core 2 Duo

Future processors

Conroe XE

By the end of 2006 Intel plans to introduce the Core 2 Extreme X6900, which is slated to clock at 3.2 GHz, while keeping the same FSB speed, L2 cache size, socket, and TDP.

According to leaked info, Intel is to release another Conroe XE in the 4th quarter of 2006, model X8000 with 3.33 GHz and 1333 MHz FSB QDR.

Penryn

The successor to the Conroe, code-named Penryn will most likely debut the 0.45 micron process that will be also used for the Kentsfield sequel, Bloomsfield. Announcements about Penryn are expected by mid-2007.

Kentsfield

Kentsfield is the codename for the first quad-core version of the Conroe processor. The new Core 2 Extreme will arrive with a clock speed of 2.67 GHz, two 4 MB L2 caches and substantially higher power consumption. The highest-end Kentsfield CPU will be branded Core 2 Extreme while the mainstream versions will be called Core 2 Quadro. Unlike AMD's 4x4 (which is two dual-core dies connected with a Hypertransport bus), Kentsfield will be a one socket solution, with two E6700 chips connected together by a 1066 MHz FSB on one MCM, resulting in lower costs but less bandwidth to the northbridge. It is expected to be released in the Fourth Quarter of 2006. Members of XtremeSystems.org have tested Kentsfield and found it to run hotter and not overclock as high as Core 2 Duos. Kentsfield will also cost signficantly more than the Core 2 Duo.

Bloomsfield

Bloomsfield is the alleged quad-core successor to the Kentsfield processor. It will have a 0.45 micron process, and be a single die design, unlike the Kentsfield, which has been compared to basically two separate Conroe cores in one socket. The Bloomsfield will have 8M of fully shared L2 cache (the Kentsfield has two separate 4M L2 caches, shared separately by each pair of processors). An across-the-board increase in bus speed (connection to the northbridge, etc.) to 1333MHz or higher is expected by this point, as all processors will be primarily limited by the bus bandwidth.

Allendale

An E4300 Allendale (1.8 GHz, 800 MT/s FSB) will be released in the 1st quarter of 2007.

Merom

Low voltage versions of Merom for use in systems such as subnotebooks are scheduled to begin shipping in Q1 2007, with the ultra-low voltage U7500 arriving in Q2 2007. As of August 2006, pricing had not been announced.

A second wave of Merom processors featuring an 800 MT/s FSB and using the new Socket P is expected to launch in April 2007. These chips will be part of the platform codenamed Santa Rosa. Low voltage versions are also planned for release in the same timeframe.

Conroe-L

Intel will offer a low-cost single-core version of Conroe, code-named "Conroe-L", starting from the second quarter 2007, according to an article on DailyTech. The new Conroe-L processors will not carry the Core nomenclature. Instead Intel is resuscitating the Pentium and Celeron brands for Conroe-L based products.

System requirements

Conroe, Conroe XE and Allendale

Conroe, Conroe XE and Allendale use Socket LGA775; however, not every motherboard is compatible with these products. Supporting chipsets are Intel's: 865PE, 945P/PL/G, 955X, 975X, P/G/Q965, Q963, 946GZ/PL (Note that 865PE support 800 MHz FSB QDR while the processors are using 1066 MHz FSB QDR); ATI's Radeon Xpress 200, RD600 and RS600; NVidia's nForce 4 SLI Intel Edition and nForce 570/590 Intel Edition; and VIA's PT880/PT880 Ultra, PT890, PM880 and PM890.

Although a motherboard may have the required chipset to support Conroe, many motherboards based on the above mentioned chipsets do not support Conroe. This is because all Conroe-based processors require a newer voltage regulator module (VRM), named VRM 11. This requirement is a result of Conroe's significantly lower power consumption, compared to the Pentium 4/D CPUs it is replacing. A motherboard that has both a supporting chipset and VRM 11 supports Conroe processors, but even then some boards will need an updated BIOS to recognize Conroe's FID (Family ID) and VID (Voltage ID).

DDR2 Memory Modules

Unlike the previous Pentium 4 and Pentium D design, the Core 2 technology sees a greater benefit from memory running synchronous with the Front Side Bus (FSB). This means that for the Conroe CPUs with FSB of 1066 MT/s, the ideal memory speed is PC2-4200. In some configurations, using PC2-5300 can actually decrease performance. Only when going to PC2-6400 is there a significant performance increase. While expensive DDR2 memory models with tighter timings do improve performance, the difference in real world games and applications is negligible.

Pricing

Core 2's pricing in lots of 1000 to OEMs is as follows (all prices in USD):

• X6800 - $999
• E6700 - $530
• E6600 - $316
• E6400 - $224
• E6300 - $183

• T7600 - $637
• T7400 - $423
• T7200 - $294
• T5600 - $241
• T5500 - $209

It should be noted that these prices are what it costs system builders such as Dell and HP to stock Core 2 processors. There are no set MSRPs for Core 2 CPUs in the retail channel - prices at retailers are usually very close to the above mentioned prices, but are dependent on what the supplier is charging to stock these CPUs as well as supply and demand.

See also

• List of Intel Core 2 microprocessors
• Intel Core

External links

News reports on the Core 2 product launch:

• Intel Core Microarchitecture
• Intel's press release announcing Core 2
• Intel's Core 2 page
• Announcing Intel Core 2 Duo
• The second coming of Intel's Core Duo

Selection of Core 2 Reviews (see the full list of 50 reviews here):

• Contemporary Dual-Core Desktop Processors Shootout
• Core 2 Duo & Extreme Processors Performance Analysis
• Intel Core 2 Performance, Overclocking, Power Usage
• Intel Core 2 Gaming Performance
• Intel's Core 2 Duo and Core 2 Extreme processors
• Intel's Core 2 Extreme & Core 2 Duo: The Empire Strikes Back
• Intel Conroe Core 2 Duo/Extreme Processors
• Game Over? Core 2 Duo Knocks Out Athlon 64
• Intel Core 2 Duo - Test
• Intel Core 2 Duo- Which Offers the Best Bang for the Buck?
• Intel's Core 2 Quadro Kentsfield: Four Cores on a Rampage