Conroe (microprocessor)

Last updated
ASRock 945GCM-S - Intel Core 2 Duo E6300 Conroe (SL9SA)-0322.jpg
Intel Core 2 Duo E6300
General information
LaunchedJuly 2006
DiscontinuedDecember 2009
CPUID code06Fx (Conroe-L: 1066x)
Product code80557
Max. CPU clock rate 1.2 GHz to 3.5 GHz
FSB speeds800 MHz to 1333 MHz
L2 cacheAllendale: 2 MB
Conroe: 4 MB
Conroe-L: 512 KB
Architecture and classification
Microarchitecture Core
Instruction set x86, x86-64
Physical specifications
  • 2 (Conroe-L: 1)
Products, models, variants
Brand name(s)

Conroe is the code name for many Intel processors sold as Core 2 Duo, Xeon, Pentium Dual-Core and Celeron. It was the first desktop processor to be based on the Core microarchitecture, replacing the NetBurst microarchitecture based Cedar Mill processor. It has product code 80557, which is shared with Allendale and Conroe-L that are very similar but have a smaller L2 cache. Conroe-L has only one processor core and a new CPUID model. The mobile version of Conroe is Merom, the dual-socket server version is Woodcrest, and the quad-core desktop version is Kentsfield. Conroe was replaced by the 45 nm Wolfdale processor.



ProcessorBrand nameModel (list)CoresL2 CacheSocketTDP
Allendale Xeon 3xxx 22 MB LGA 775 65 W
Conroe 3xxx 2-4 MB
Conroe and
Core 2 Duo E4xxx 22 MBLGA 77565 W
E6xx0 2-4 MB
Conroe-CL E6xx5 2-4 MB LGA 771
Conroe-XE Core 2 Extreme X6xxx 24 MBLGA 77575 W
Allendale Pentium Dual-Core E2xxx 21 MBLGA 77565 W
Allendale Celeron E1xxx 2512 KBLGA 77565 W
Conroe-L 4x0 135 W
Conroe-CL 4x5 LGA 77165 W


The first Intel Core 2 Duo branded processor cores, code-named Conroe, were launched on July 27, 2006, at Fragapalooza, a yearly gaming event in Edmonton, Alberta, Canada. These processors were fabricated on 300 mm wafers using a 65 nm manufacturing process, and intended for desktop computers, as a replacement for the Pentium 4 and Pentium D branded CPUs. Intel has claimed that Conroe provides 40% more performance at 40% less power compared to the Pentium D; the E6300, lowest end of the initial Conroe lineup, is able to match or even exceed the former flagship Pentium Extreme Edition 965 in performance despite a massive 50% clock frequency deficit. All Conroe processors are manufactured with 4 MB L2 cache; however, due to manufacturing defects or possibly for marketing purposes, the E6300 and E6400 versions based on this core have half their cache disabled, leaving them with only 2 MB of usable L2 cache. These Conroe-based E6300 and E6400 CPUs have the B2 stepping.

The lower end E6300 (1.86 GHz) and E6400 (2.13 GHz), both with a 1066 MHz FSB (64-bits wide), were released on July 27, 2006. Traditionally, CPUs of the same family with less cache simply have the unavailable cache disabled, since this allows parts that fail quality control to be sold at a lower rating. When yields improve, they may be replaced with versions that only have the cache amount needed on the die, to bring down manufacturing cost. At launch time, Intel's prices for the Core 2 Duo E6300 and E6400 processors were US$183 and US$224 each in quantities of 1000. Conroe CPUs have improved capabilities over previous models with similar processor clock rates. According to reviews, the larger 4 MB L2 cache vs. the smaller 2 MB L2 cache at the same frequency and FSB can provide a 0–9% performance gain with certain applications and 0–16% performance gain with certain games. [1] [2] The higher end Conroe processors are the E6600 (2.4 GHz) and E6700 (2.67 GHz) Core 2 Duo models. The family has a 1066  MHz front side bus, 4 MB shared L2 cache, and 65 watts TDP. These processors have been tested against AMD's then-current top performing processors (Athlon 64 FX Series), which were, until this latest Intel release, the highest performance X86 CPUs available. Conroe chips also produce less heat than their predecessors — a benefit of the new 65 nm technology and the more efficient microarchitecture. At launch time, Intel's prices for the Core 2 Duo E6600 and E6700 processors were US$316 and US$530, respectively, each in quantities of 1000.

E6320 and E6420 Conroe CPUs at 1.86 and 2.13 GHz respectively were launched on April 22, 2007 featuring a full 4 MB of cache and are considered Conroes.

Intel Core 2 Duo E6300 processor ASRock 945GCM-S - Intel Core 2 Duo E6300 Conroe (SL9SA)-0322.jpg
Intel Core 2 Duo E6300 processor

Intel released four additional Core 2 Duo Processors on July 22, 2007. The release coincided with that of the Intel Bearlake (x3x) chipsets. The new processors are named Core 2 Duo E6540, E6550, E6750, and E6850. Processors with a number ending in "50" have a 1333 MHz FSB. The processors all have 4 MB of L2 cache. Their clock frequency is similar to that of the already released processors with the same first two digits (E6600, E6700, X6800). [3] An additional model, the E6540, was launched with specifications similar to the E6550 but lacking Intel Trusted Execution Technology and vPro support. These processors are stated to compete with AMD's Phenom processor line and are therefore priced below corresponding processors with a 1066 MHz FSB. [4]

All remaining Conroe Core 2 processors have been phased out in March 2009.

Conroe XE

The Core 2 Extreme was officially released on July 29, 2006. However, some retailers appeared to have released it on July 13, 2006, though at a higher premium. Currently, the Core 2 Extreme X6800 is the only dual core Core 2 Extreme processor available. The less powerful E6x00 models of Core 2 Duo were scheduled for simultaneous release with the X6800, which are both available at this time. It uses the Conroe XE core and replaces the dual-core Pentium Extreme Edition processors. The Core 2 Extreme X6800 has a clock rate of 2.93 GHz and a 1066 MHz FSB, although it was initially expected to be released with a 3.33 GHz clock rate and a 1333 MHz FSB. The TDP for the X6800 is 75watts, higher than the TDPs of regular Core 2 Duo CPUs, which have a 65 watt TDP. With SpeedStep enabled, the average temperature of the CPU when idle is essentially that of the ambient atmosphere with its fan running at 1500 RPM. [5]

At launch time, Intel's price for the Core 2 Extreme X6800 was US$999 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 higher clock rate and unlocked multiplier, the usual advantages of the "Extreme Edition." The fully unlocked multiplier is of use to enthusiasts as it allows the user to set the clock rate higher than shipping frequency without modifying the FSB frequency unlike mainstream Core 2 Duo models whose multipliers are downward unlocked only.


Allendale was originally the name for the E4000 processors, which use a low-cost version of the Conroe core. They feature a lower front side bus frequency of 800 MHz instead of 1066 MHz and only half the L2 cache (2 MB, similar to the Core 2 Duo E6300 and E6400), offering a smaller die size and therefore greater yields. Most media have subsequently applied the name Allendale to all LGA 775 processors with steppings L2 and M0, while Intel refers to all of these as Conroe.

The Core 2 Duo E4300 [6] uses an Allendale core, released on January 21, 2007. Allendale processors are produced in the LGA 775 form factor, on the 65 nm process node. Initial list price per processor in quantities of one thousand for the E4300 was US$163. A standard OEM price was US$175, or US$189 for a retail package. The price was cut on April 22, 2007, [7] when the E4400 was released at $133 and the E4300 dropped to $113. A new E2000 series of Allendale processors with half their L2 cache disabled was released in mid-June 2007 under the Pentium Dual-Core brand name. The working cache memory was reduced by half again when the Allendale core was released under Intel's Celeron brand; the Celeron E1000 processors have a 512k L2 cache shared between its two cores.

Subsequent E4000 Allendale processors were introduced as E4500 and E4600. The final E4700 processor was using the G0 stepping instead of M0, which makes it a Conroe core. The E4000 processors were discontinued on March 6, 2009.

E6300 and E6400 CPUs, as well as their Xeon 3040 and 3050 counterparts, have been made using the original 4 MB B2 stepping with half their L2 cache disabled prior to Q1 2007, but using the 2 MB L2 stepping later. This caused contention regarding whether or not the previously available versions were specimens of the Allendale core. Only the newer cores are now commonly referred to as Allendale.

Quoted from The Tech Report:

You'll find plenty of sources that will tell you the code name for these 2 MB Core 2 Duo processors is "Allendale," but Intel says otherwise. These CPUs are still code-named "Conroe," which makes sense since they're the same physical chips with half of their L2 cache disabled. Intel may well be cooking up a chip code-named Allendale with 2 MB of L2 cache natively, but this is not that chip. [8]


The Conroe-L Celeron is a single-core processor built on the Core microarchitecture and is clocked much lower than the Cedar Mill Celerons, but still outperforms them. It is based on the 65 nm Conroe-L core, and uses a 400-series model number sequence. The FSB was increased from 533 MHz to 800 MHz in this generation, and the TDP was decreased from 65 W to 35 W. Traditionally with Celerons, it does not have Intel VT-x support or SpeedStep. All Conroe-L models are single-core processors for the value segment of the market, much like the AMD K8-based Sempron. The product line was launched on June 5, 2007.

On October 21, 2007, Intel presented a new processor for its Intel Essential Series. The full name of the processor is a Celeron 220 and is soldered on the D201GLY2 motherboard. With 1.2 GHz and a 512 KB second level cache it has a TDP of 19 Watt and can be cooled passively. The Celeron 220 is the successor of the Celeron 215 which is based on a Yonah core and used on the D201GLY motherboard. This processor is exclusively used on the mini-ITX boards targeted to the sub-value market segment. [9]


Conroe-CL is a version of Conroe with the LGA 771 Socket otherwise used in Woodcrest. Unlike real Woodcrest, they are only usable in single-CPU configurations. The three Conroe-CL processors that are known are sold as Core 2 Duo E6305, E6405 and Celeron 445. These processors will not work in regular LGA 775 mainboards but are typically used in blade servers that also use Woodcrest or other DP server processors.

See also

Related Research Articles

Celeron Brand name by Intel

Celeron is a brand name given by Intel to a number of different low-end IA-32 and x86-64 computer microprocessor models targeted at low-cost personal computers.

Pentium 4 is a series of single-core CPUs for desktops, laptops and entry-level servers manufactured by Intel. The processors were shipped from November 20, 2000 until August 8, 2008. The production of Netburst processors was active from 2000 until May 21, 2010.

Pentium III Line of desktop and mobile microprocessors produced by Intel

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 most notable differences were the addition of the Streaming SIMD Extensions (SSE) instruction set, and the introduction of a controversial serial number embedded in the chip during manufacturing.

The Pentium M is a family of mobile 32-bit single-core x86 microprocessors introduced in March 2003 and forming a part of the Intel Carmel notebook platform under the then new Centrino brand. The Pentium M processors had a maximum thermal design power (TDP) of 5–27 W depending on the model, and were intended for use in laptops. They evolved from the core of the last Pentium III–branded CPU by adding the front-side bus (FSB) interface of Pentium 4, an improved instruction decoding and issuing front end, improved branch prediction, SSE2 support, and a much larger cache. The first Pentium M–branded CPU, code-named Banias, was followed by Dothan. The Pentium M-branded processors were succeeded by the Core-branded dual-core mobile Yonah CPU with a modified microarchitecture.

Tejas was a code name for Intel's microprocessor, which was to be a successor to the latest Pentium 4 with the Prescott core and was sometimes referred to as Pentium V. Jayhawk was a code name for its Xeon counterpart. The cancellation of the processors in May 2004 underscored Intel's historical transition of its focus on single-core processors to multi-core processors.

Xeon Line of Intel server processors

Xeon is a brand of x86 microprocessors designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server, and embedded system markets. It was introduced in June 1998. Xeon processors are based on the same architecture as regular desktop-grade CPUs, but have advanced features such as support for ECC memory, higher core counts, more PCI Express lanes, support for larger amounts of RAM, larger cache memory and extra provision for enterprise-grade reliability, availability and serviceability (RAS) features responsible for handling hardware exceptions through the Machine Check Architecture. They are often capable of safely continuing execution where a normal processor cannot due to these extra RAS features, depending on the type and severity of the machine-check exception (MCE). Some also support multi-socket systems with two, four, or eight sockets through use of the Quick Path Interconnect (QPI) bus.

Slot 1 Physical and electrical specification for the connector used by some Intel microprocessors

Slot 1 refers to the physical and electrical specification for the connector used by some of Intel's microprocessors, including the Pentium Pro, Celeron, Pentium II and the Pentium III. Both single and dual processor configurations were implemented.

The NetBurst microarchitecture, called P68 inside Intel, was the successor to the P6 microarchitecture in the x86 family of central processing units (CPUs) made by Intel. The first CPU to use this architecture was the Willamette-core Pentium 4, released on November 20, 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst. In mid-2004, Intel released the Foster core, which was also based on NetBurst, thus switching the Xeon CPUs to the new architecture as well. Pentium 4-based Celeron CPUs also use the NetBurst architecture.

The Pentium D brand refers to two series of desktop dual-core 64-bit x86-64 microprocessors with the NetBurst microarchitecture, which is the dual-core variant of Pentium 4 "Prescott" 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 limit exemplified by the Presler's 130 watt thermal design power. 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.

The P6 microarchitecture is the sixth-generation Intel x86 microarchitecture, implemented by the Pentium Pro microprocessor that was introduced in November 1995. It is frequently referred to as i686. It was succeeded by the NetBurst microarchitecture in 2000, but eventually revived in the Pentium M line of microprocessors. The successor to the Pentium M variant of the P6 microarchitecture is the Core microarchitecture which in turn is also derived from the P6 microarchitecture.

The Intel Core microarchitecture is a multi-core processor microarchitecture unveiled by Intel in Q1 2006. It is based on the Yonah processor design and can be considered an iteration of the P6 microarchitecture introduced in 1995 with Pentium Pro. High power consumption and heat intensity, the resulting inability to effectively increase clock rate, and other shortcomings such as an inefficient pipeline were the primary reasons why Intel abandoned the NetBurst microarchitecture and switched to a different architectural design, delivering high efficiency through a small pipeline rather than high clock rates. The Core microarchitecture initially did not reach the clock rates of the NetBurst microarchitecture, even after moving to 45 nm lithography. However after many generations of successor microarchitectures which used Core as their basis, Intel managed to eventually surpass the clock rates of Netburst with the Devil's Canyon microarchitecture reaching a base frequency of 4 GHz and a maximum tested frequency of 4.4 GHz using 22 nm lithography.

Intel Core 2 Processor family by Intel

Intel Core 2 is the processor family 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 multi-chip module. The Core 2 range was the last flagship range of Intel desktop processors to use a front-side bus.

Pentium Brand of microprocessors produced by Intel

Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel since 1993. In their form as of November 2011, Pentium processors are considered entry-level products that Intel rates as "two stars", meaning that they are above the low-end Atom and Celeron series, but below the faster Intel Core lineup, and workstation Xeon series.

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. The processors are based on either the 32-bit Yonah or 64-bit Merom-2M, Allendale, and Wolfdale-3M core, targeted at mobile or desktop computers.

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 the product code 80537, which is shared with Merom-2M and Merom-L that are very similar but have a smaller L2 cache. Merom-L has only one processor core and a different CPUID model. The desktop version of Merom is Conroe and the dual-socket server version is Woodcrest. Merom was manufactured in a 65 nanometer process, and was succeeded by Penryn, a 45 nm version of the Merom architecture. Together, Penryn and Merom represented the first 'tick-tock' in Intel's Tick-Tock manufacturing paradigm, in which Penryn was the 'tick' to Merom's 'tock'.

Kentsfield (microprocessor)

Kentsfield is the code name of the first Intel desktop quad core CPU branded Core 2, released on November 2, 2006. The top-of-the-line Kentsfields were Core 2 Extreme models numbered QX6xx0, while the mainstream ones branded Core 2 Quad were numbered Q6xx0. All of them featured two 4 MB L2 caches. The mainstream 65 nanometer Core 2 Quad Q6600, clocked at 2.4 GHz, was launched on January 8, 2007 at US$851. July 22, 2007 marked the release of the Q6700, and Extreme QX6850 Kentsfields at US$530 and US$999 respectively along with a further price reduction of the Q6600 to US$266. Both Kentsfield and Kentsfield XE use product code 80562.

Penryn (microprocessor)

Penryn is the code name of a processor from Intel that is sold in varying configurations as Core 2 Solo, Core 2 Duo, Core 2 Quad, Pentium and Celeron.

Wolfdale (microprocessor)

Wolfdale is the code name for a processor from Intel that is sold in varying configurations as Core 2 Duo, Celeron, Pentium and Xeon. In Intel's Tick-Tock cycle, the 2007/2008 "Tick" was Penryn microarchitecture, the shrink of the Core microarchitecture to 45 nanometers as CPUID model 23. This replaced the Conroe processor with Wolfdale.


  1. "Core 2 Duo: 2 or 4 MB cache? (French)". Matbe. Archived from the original on 2006-07-05. Retrieved 2006-06-29.
  2. "Intel's Core 2 Duo processors". Bit-Tech. Archived from the original on 2012-01-21. Retrieved 2006-07-14.
  3. ""Conroe" Refresh Details Unveiled". DailyTech. Archived from the original on 2006-10-21. Retrieved 2006-10-17.
  4. "Intel Processor Price List" (PDF). Intel. Archived from the original (PDF) on 2007-04-10. Retrieved 2007-07-24.
  5. Schmid, Patrick; Töpelt, Bert. "Game". Tom's Guide Publishing. Retrieved 2006-07-17.
  6. "Core 2 Duo E4300". Archived from the original on 2009-05-02. Retrieved 2009-08-24.
  7. Allendale price cuts
  8. "Cool and Cheap Screamers from Intel and AMD". The Tech Report. 2006-08-08. Archived from the original on 2006-08-20. Retrieved 2006-11-22.
  9. "NEW CELERON 220". xtreview. 2006-10-15. Retrieved 2007-10-22.