Kentsfield (microprocessor)

Lore & Background

Kentsfield processors consist of two separate silicon dies, each equivalent to a single Core 2 Duo, mounted on one multi-chip module. This design reduced manufacturing costs but limited each die's bandwidth to the northbridge compared to separate sockets. The thermal design power of Kentsfield CPUs roughly doubled that of similarly clocked Core 2 Duo processors, with the Q6600 rated at 105 W and the QX6700 and QX6800 at 130 W.

The mainstream Core 2 Quad Q6600 launched on January 8, 2007 at US$851, later reduced to US$530 on April 7, 2007, and further to US$266 after July 22, 2007. The Core 2 Extreme QX6700 debuted on November 2, 2006 at US$999 and was discontinued on January 4, 2008. The QX6800, clocked at 2.93 GHz, was released on April 8, 2007 at US$1,199 for high-end OEM systems. The QX6850, at 3.0 GHz with a 1333 MT/s front-side bus, launched on July 22, 2007 at US$999.

The dual-core desktop counterpart of Kentsfield is Conroe, and its server versions are Clovertown (Xeon 53xx) and Tigerton (Xeon 73xx). Kentsfield was succeeded by the 45 nm Yorkfield processor.

Reader's Guide

Kentsfield's significance lies in bringing quad-core processing to the desktop market. Its multi-chip module design allowed Intel to offer four cores at a lower cost than a monolithic die, though it came with trade-offs: higher power consumption and shared memory/I/O bandwidth between the two dies. The architecture primarily benefited applications that could be parallelized into a few threads, such as audio and video transcoding, data compression, 3D rendering, and ray-tracing. In multi-threaded games like Crysis and Gears of War, which handle simultaneous tasks such as AI, audio, and physics, quad-core CPUs could approach a performance increase proportional to the number of cores, assuming proper software threading. However, some tests showed Crysis failed to use more than two cores at once. The separated L2 cache (one per dual-core module) could simplify parallelizing tasks like pixel or vertex shading on systems with limited integrated graphics. Overhead from coordinating multiple threads and potential bottlenecks from shared resources remained considerations. Kentsfield XE variants featured unlocked multipliers, continuing the tradition of Intel's Extreme Edition processors.

Did You Know?

• Kentsfield was the first Intel desktop quad-core processor, released on November 2, 2006.
• It consists of two separate Core 2 Duo dies on a single multi-chip module.
• The Core 2 Extreme QX6700 had an unlocked multiplier and was discontinued on January 4, 2008.
• The Q6600's price dropped from US$851 at launch to US$266 by late July 2007.