Kentsfield (microprocessor)
Encyclopedia
Kentsfield is the code name of the first Intel desktop quad core CPU branded Core 2 (and Xeon for lower-end servers and workstations), 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 cache
s. The mainstream Core 2 Quad Q6600, clocked at 2.4 GHz, was launched on January 8, 2007 at US$851 (reduced to US$530 on April 7, 2007). 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.
branded CPUs, the Kentsfields comprise two separate silicon dies (each equivalent to a single Core 2 duo) on one MCM
. This results in lower costs but lesser share of the bandwidth from each of the CPUs to the northbridge
than if the dies were each to sit in separate sockets as is the case for example with the AMD Quad FX platform. Also, as might be predicted from the two-die MCM configuration, the max power consumption (TDP
) of the Kentsfield (QX6800 - 130 watt
s,
QX6700 - 130 W,
Q6600 - 95 W
) has been found to be double that of its similarly clocked Core 2 Duo counterpart.
The multiple cores
of the Kentsfield most benefit applications that can easily be broken into a small number of parallel threads
(such as audio and video transcoding, data compression
, video editing
, 3D rendering
and ray-tracing). To take a specific example, multi-threaded games such as Crysis
and Gears of War
which must perform multiple simultaneous tasks such as AI, audio and physics benefit from the quad-core CPUs. In such cases, the processing performance may increase relative to that of a single-CPU system by a factor approaching the number of CPUs. This should, however, be considered an upper limit as it presupposes the user-level software is well-threaded. To return to the above example, some tests have demonstrated that Crysis fails to take advantage of more than two cores at any given time. On the other hand, the impact of this issue on broader system performance can be significantly reduced on systems which frequently handle numerous unrelated simultaneous tasks such as multi-user environments or desktops which execute background processes while the user is active. There is still, however, some overhead involved in coordinating execution of multiple processes or threads and scheduling them on multiple CPUs which scales with the number of threads/CPUs. Finally, on the hardware level there exists the possibility of bottlenecks arising from the sharing of memory and/or I/O bandwidth between processors.
The Core 2 Extreme QX6800 clocked at 2.93 GHz was released on April 8, 2007, at US$1,199. It had a 130 W
TDP
thermal envelope, and was intended for high end OEM-only systems.
The Core 2 Extreme QX6850 clocked at 3.0 GHz was launched on July 22, 2007, at US$999. It featured a faster 1333 MT/s FSB
. Simultaneously, the previously available Extreme QX6700 was reduced in price.
, the server versions of Kentsfield are the dual-processor Clovertown (Xeon 53xx) and the multi-processor Tigerton (Xeon 73xx).
processor.
Cache
In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
s. The mainstream Core 2 Quad Q6600, clocked at 2.4 GHz, was launched on January 8, 2007 at US$851 (reduced to US$530 on April 7, 2007). 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.
Variants
| Processor | Brand name | Model (list) | Cores | L2 Cache | Socket | TDP |
|---|---|---|---|---|---|---|
| Kentsfield | 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:... |
32xx | 4 | 2x4 MiB | LGA 775 | 95-105 W |
| Kentsfield | Core 2 Quad | Q6xxx | 4 | 2x4 MiB | LGA 775 | 95-105 W |
| Kentsfield XE | Core 2 Extreme | QX6xxx | 4 | 2x4 MiB | LGA 775 | 130 W |
Kentsfield
Analogous to the Pentium DPentium D
The Pentium D brand refers to two series of desktop dual-core 64-bit x86-64 microprocessors with the NetBurst microarchitecture 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,...
branded CPUs, the Kentsfields comprise two separate silicon dies (each equivalent to a single Core 2 duo) on one MCM
Multi-Chip Module
A multi-chip module is a specialized electronic package where multiple integrated circuits , semiconductor dies or other discrete components are packaged onto a unifying substrate, facilitating their use as a single component...
. This results in lower costs but lesser share of the bandwidth from each of the CPUs to 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...
than if the dies were each to sit in separate sockets as is the case for example with the AMD Quad FX platform. Also, as might be predicted from the two-die MCM configuration, the max power consumption (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...
) of the Kentsfield (QX6800 - 130 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s,
QX6700 - 130 W,
Q6600 - 95 W
) has been found to be double that of its similarly clocked Core 2 Duo counterpart.
The multiple cores
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
of the Kentsfield most benefit applications that can easily be broken into a small number of parallel threads
Thread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
(such as audio and video transcoding, data compression
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
, video editing
Video editing software
Video editing software, is application software which handles the post-production video editing of digital video sequences on a computer non-linear editing systems...
, 3D rendering
Rendering (computer graphics)
Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
and ray-tracing). To take a specific example, multi-threaded games such as Crysis
Crysis
Crysis is a science fiction first-person shooter video game developed by Crytek , published by Electronic Arts for Microsoft Windows, and released in November 2007. It is the first game of a trilogy. A separate game entitled Crysis Warhead was released on September 12, 2008, and follows similar...
and Gears of War
Gears of War
Gears of War is a military science fiction third-person shooter video game developed by Epic Games and published by Microsoft Game Studios...
which must perform multiple simultaneous tasks such as AI, audio and physics benefit from the quad-core CPUs. In such cases, the processing performance may increase relative to that of a single-CPU system by a factor approaching the number of CPUs. This should, however, be considered an upper limit as it presupposes the user-level software is well-threaded. To return to the above example, some tests have demonstrated that Crysis fails to take advantage of more than two cores at any given time. On the other hand, the impact of this issue on broader system performance can be significantly reduced on systems which frequently handle numerous unrelated simultaneous tasks such as multi-user environments or desktops which execute background processes while the user is active. There is still, however, some overhead involved in coordinating execution of multiple processes or threads and scheduling them on multiple CPUs which scales with the number of threads/CPUs. Finally, on the hardware level there exists the possibility of bottlenecks arising from the sharing of memory and/or I/O bandwidth between processors.
Kentsfield XE
The first Kentsfield XE, named Core 2 Extreme QX6700 (product code 80562) and clocked at 2.67 GHz, was released on November 2, 2006, at US$999. January 4, 2008, marks its discontinuation. It featured the Kentsfield XE core, and complemented the Core 2 Extreme X6800 dual-core processor based on the Conroe XE core. Like their dual core Extreme predecessors, CPUs with the Kentsfield XE core had unlocked multipliers.The Core 2 Extreme QX6800 clocked at 2.93 GHz was released on April 8, 2007, at US$1,199. It had a 130 W
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
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...
thermal envelope, and was intended for high end OEM-only systems.
The Core 2 Extreme QX6850 clocked at 3.0 GHz was launched on July 22, 2007, at US$999. It featured a faster 1333 MT/s 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....
. Simultaneously, the previously available Extreme QX6700 was reduced in price.
Related processors
The dual-core desktop version of Kentsfield is ConroeConroe (microprocessor)
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...
, the server versions of Kentsfield are the dual-processor Clovertown (Xeon 53xx) and the multi-processor Tigerton (Xeon 73xx).
Successor
Kentsfield was subsequently replaced by the 45 nm YorkfieldYorkfield (microprocessor)
Yorkfield is the code name for some Intel processors sold as Core 2 Quad 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, replacing Kentsfield, the previous model.Like its...
processor.