CPU Guide

Intel Core 2 Extreme QX6850 review

Intel Core 2 Extreme QX6850: Quad-Core at 3GHz

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The Long Awaited FSB Upgrade

The Long Awaited FSB Upgrade

Exactly this time last year, Intel was well immersed in the Core phenomenon that gripped the CPU industry as a whole with the Core 2 Duo desktop processors setting industry leading performance and an all-time low for thermal and power requirements. Peering in to their processor lineup details, as per tradition they had an extreme performance part that was simply coined as the Core 2 Extreme. However, it was nothing more than the higher clocked version of the Core 2 Duo processors and offered virtually nothing more which otherwise a savvy overclocker would have achieved by obtaining a lower clocked variety (and this was highly desirable since the Core 2 processors were exceptional overclockers). What would have really made the Core 2 Extreme an extreme processor in our opinion is a native 1333MHz front side bus (FSB) as opposed to the normal 1066MHz FSB of the standard processors. With the Intel P965 Express chipsets having high tolerance in FSB speeds, we saw that as a natural step-up.

Instead, the Core 2 Extreme series was greeted with quad-core processors just three months into their official launch - which is quite a milestone for desktop processing prowess. This was the Core 2 Extreme QX6700. Based on the Kentsfield core which is essentially two Conroe silicon dies (used on the dual-core Core 2 series) placed on the same processor packaging (you can read more about this here ). Despite its four brains, the processor still ran off the 1066MHz FSB. While that didn't present itself as the bottleneck, software was still lacking to take advantage of the four processing cores as noted in our review.

In more recent times, Intel launched the new 3-series chipsets in which many of them support 1333MHz FSB natively. Oddly though, they didn't choose to launch any processors that were officially capable of that specification. While we concede that Intel is currently basking in the glory of occupying the CPU throne not only for its performance and capabilities but also technological and production advantages, we felt that the new platform didn't carry much weight on its own as it would have garnered much better traction if corresponding processors were made available too. Finally today on July 17th, Intel has answered our calls and is letting out a slew of 1333MHz FSB processors and to give consumers a real reason to take the 3-series platform a lot more seriously. Core 2 Duo processors of the upper echelon will get the 1333MHz FSB treatment as well as a new quad-core SKU, the Core 2 Extreme QX6850. For today, our focus is on the US$999 Core 2 Extreme QX6850 and here's how it stacks up with the rest of the existing desktop multi-core processors:-

High-End Multi-Core Processors Compared
Processor Name Core 2 Extreme (quad-core) Core 2 Extreme (dual-core) Core 2 Quad Core 2 Duo AMD Athlon 64 X2
Processor Model QX6850, QX6800, QX6700 X6800 Q6600 E6320, E6420, E6600, E6700 6000+
Processor Frequency 3.0GHz, 2.93GHz, 2.67GHz 2.93GHz 2.40GHz 1.86GHz, 2.13GHz, 2.40GHz, 2.67GHz 3.0GHz
No. of Cores 4 2 4 2 2
Front Side Bus (MHz) 1333, 1066 1066 1066 1066 -
HyperTransport Bus - - - - 1GHz (2000MT/s)
L1 Cache (data + instruction) (32KB + 32KB) x 4 (32KB + 32KB) x 2 (32KB + 32KB) x 4 (32KB + 32KB) x 2 (64KB + 64KB) x 2
L2 Cache 4MB x 2 4MB 4MB x 2 4MB 1MB x 2
Memory Controller External Dual Channel (up to DDR2-800) External Dual Channel (up to DDR2-800) External Dual Channel (up to DDR2-800) External Dual Channel (up to DDR2-800) Integrated Dual Channel (up to DDR2-800)
VID (V) 0.85 - 1.50 0.85 - 1.3625 0.85 - 1.50 0.85 - 1.3625 1.35 - 1.40
Icc (max) (A) 125 90 115 75 90.4
TDP (W) 130 75 105 65 125
Execute Disable Bit Yes Yes Yes Yes Yes
Intel EM64T / AMD64 Yes Yes Yes Yes Yes
Enhanced Intel SpeedStep Technology (EIST) / AMD Cool 'n' Quiet Yes Yes Yes Yes Yes
Virtualization Technology Yes Yes Yes Yes Yes
Packaging LGA775 LGA775 LGA775 LGA775 AM2
Process Technology 65nm 65nm 65nm 65nm 90nm SOI
Processor Codename Kentsfield Conroe Kentsfield Conroe Windsor
Die Size 286mm² 143mm² 286mm² 143mm² 230mm²
No. of Transistors 582 million 291 million 582 million 291 million 227.4 million