Intel Core 2 Extreme QX6800 Processor Review

Introduction

After an initial flurry of new product releases, including a range of Core 2 Duo, Extreme and Quad processors, Intel suddenly went silent, with only a slower 2.4 GHz quad core emerging since November of 2006. Meanwhile, AMD was hard at work with their QuadFX platform and a series of Athlon 64 X2 releases that culminated with the 3.0 GHz Athlon 64 X2 6000+. AMD also engaged in repeated price wars, while Intel didn't even flinch, secure in their knowledge that the Core 2 represented the top architecture of this processor generation. Intel has also been hyping its 45nm Core 2 migration, with its upcoming Penryn core offering higher clock speeds and some architectural improvements. To bridge that gap, Intel has introduced the Core 2 Extreme QX6800, a 2.93 GHz quad core powerhouse.

The Core 2 Extreme QX6800 Processor

The Core 2 Extreme QX6800 still makes use of the Kentsfield quad core architecture, which takes two processors and combines them onto a single package. It 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. While the Core 2 Duo can dynamically allocate its 4MB of Advanced Smart Cache, the Kentsfield quad exists as a 2x4MB design, rather than 8MB of integrated L2 cache. This also means that the processors cannot share data internally, instead communicating along the slower CPU bus, and using the same memory interface.

The Core 2 Extreme QX6800 still includes a total L2 of 8MB, with each Core 2 unit able to dynamically allocate its own 4MB. The processor's L2 bus is fully 256-bit, the L1 cache has 32KB instruction/32KB data caches per core, and each features 8-way associativity. The Core 2 Extreme QX6800 includes support for Intel SpeedStep technology, which is a big plus, as with four cores under the hood, power management is a major concern. Like all Intel Extreme processors, this has an unlocked multiplier, allowing even greater overclocking freedom. The latest quad core processor also supports features like Execute Disable Bit, Intel 64 Technology, SSE4, and Intel Virtualization Technology, among others.

The big difference this time out is the clock speed. The Core 2 Extreme QX6800 runs at 2.93 GHz, equaling the Core 2 Extreme X6800 dual core as the fastest Intel desktop processor. It joins the Intel quad core family that also includes the 2.66 GHz Core 2 Extreme QX6700 and 2.4 GHz Core 2 Quad Q6600. The Core 2 Extreme QX6800 supports the LGA775 socket (opening up some upgrade opportunities), runs on the 1066 MHz bus, and features 8MB (2x4MB) of combined L2 cache. Although the clock speed has been bumped up another 266 MHz, the processor's 1.35V max voltage and 130W TDP specifications remain consistent with the 2.66 GHz Core 2 Extreme QX6700. This suggests that Intel has improved its 65nm process, and can now give out 2.93 GHz under the same thermal window.

The only issue we can find concerns the product name. As more Core 2 Duo, Extreme and Quad models are released, the branding becomes even more confusing to end users, especially as it concerns processors like the Core 2 Extreme QX6800. Intel made the right move with the Core 2 Quad brand, easily differentiated from the Core 2 Duo. It's the same with the numeric suffixes (6600, 6700, and 6800), which over time can be linked to core speeds, but adding a "Q" prefix is not the optimal solution for Core 2 Extreme quad core buyers. Many retailers have started referring to these as Core 2 Extreme Quad processors anyway, so here's hoping Intel follows suit with their 45nm product lines.