Throughout 2006, AMD and Intel took part in a seesaw battle for CPU market supremacy. AMD and their dual core Athlon 64 FX held the edge through the first half, before Intel answered back with the impressive Core 2 Duo and Extreme processors in July. After that, it was time for a good old-fashioned price war, with both AMD and Intel slicing their inventory, with consumers reaping the benefits of a value-filled market. In some ways, the dual core market seemed to be played out, and Intel went straight for the quad core glory by releasing the 2.66 GHz Core 2 Extreme QX6700. Intel is now following this up with a more mainstream release, and a new product name, all bundled up in a 2.4 GHz Core 2 Quad Q6600 package.
The Kentsfield quad core is very similar to the initial Pentium D 800 series, in that it takes two processors and combines them onto a single package. This design has obvious benefits, with an accelerated time to market being a primary one, and something that has allowed Intel to hit the quad core milestone with no response from AMD. Of course, this differs from a specialized multi-core design like the Core 2 or Athlon 64 X2, as the two dies exist as separate entities and there is no sharing of internal resources. This also means that the processors cannot share data internally, instead communicating along the slower CPU bus, and sharing the same memory interface.
Although the Kentsfield does include two 4MB Core 2 processors, it also means that many Core 2 features are not fully realized. Core 2 processors feature either 2MB or 4MB of Advanced Smart Cache, which is shared between the two cores. This allows the Core 2 processor a great deal of flexibility, and it could allocate all 4MB of L2 cache to a single core in gaming scenarios, while dynamically shifting the L2 cache between cores in a multi-threading environment. This type of flexibility is not present in the Kentsfield core, there is no facility for sharing of the 8MB of total L2 cache, and instead it acts like dual Core 2 processors, each sharing 4MB of L2 cache. This also affects the entire processor, with absolutely no shared resources between the dual processor dies, resulting in duplication between the two distinct processors.
There are still some advantages to the architecture. The entire L2 cache is not shared, but there is still a total of 8MB, with each Core 2 unit able to dynamically allocate its own 4MB share. The Core 2's L2 bus is fully 256-bit, and the L1 cache is 32KB instruction/32KB data caches per core, and each has 8-way associativity. The Core 2 includes support for Intel SpeedStep technology, and so too does the quad core Kentsfield. This is a huge advantage, as with four cores under the same roof, power management is a major concern. The Kentsfield also supports features like Execute Disable Bit, Intel 64 Technology, SSE4, and Intel Virtualization Technology, among others.
The Core 2 Quad Q6600 features an Intel Kentsfield quad core running at 2.4 GHz. The processor supports the LGA775 socket, features 8MB (2x4MB) of combined L2 cache, and runs on the 1066 MHz front-side bus. The processor's max voltage is 1.325V and it has a TDP (Thermal Design Power) of 105W, both of which have dropped from the 1.35V and 130W TDP specifications of the 2.66 GHz Core 2 Extreme QX6700. As with other quad core Kentsfield processors, the Core 2 Quad Q6600 is also compatible with some existing LGA775 motherboards, allowing a level of upgradeability for end users.
As the Core 2 Quad Q6600 is a Kentsfield running at 2.4 GHz, the basics remain the same. It features an integrated heat spreader and uses a standard LGA775 interface. One big improvement comes in the new product name, which got a little confusing with the Core 2 Extreme QX6700 quad core release. By instituting the Core 2 Quad brand, Intel will make it easier for end users to differentiate between Core 2 dual and quad core models. Even the model numbers are becoming easier to use, and the numeric suffixes (6600, 6700, and 6800) are easily linked to the end core speeds.