Intel has yet to officially announce its latest series of CPUs - Core 2 Quad - but the company was kind enough to supply us with several samples to benchmark and evaluate. However, as we're seeing them so early, there's a chance that the model numbers and prices will have changed by the time the chips are available to buy in early 2007.
As the name suggests, the Core 2 Quad-series of CPUs all have four physical cores. However, as with the Core 2 Extreme QX6700, they aren't native quad-core CPUs. This means that Intel has manufactured two Core 2 Duos separately, and then assembled them together in the same CPU die. As a result, although the Core 2 Quad has 8MB of Level 2 cache, each pair of cores can only access 4MB. Both models have a 266MHz FSB (1,066MHz effective), but run at different clock speeds - the Q6400 runs at 2.13GHz and the Q6600 runs at 2.4GHz. Because of this, they have slightly lower TDPs of 105W, 25W less than QX6700, which has a toasty-warm TDP of 130W.
In non-multithreaded applications, which comprise the majority of apps and games, the Q6400 performs almost identically to the cheaper Core 2 Duo E6400, while the Q6600 performs very similarly to the E6600. However, in fully multithreaded apps, such as DVD encoders, 3D renderers and Folding@home, the Core 2 Quads shine.
As the Q6400 and Q6600 output less waste heat than the QX6700, they can be overclocked to around 2.8GHz using a decent air cooler such as the Arctic Cooling Freezer 7 Pro. Both CPUs can easily be overclocked to over 3GHz, but water cooling is mandatory at this speed (and above), unless you don't mind using a CPU cooler with a noisy, fast-spinning fan.
Both the Q6400 and Q6600 cost a considerable amount more than a Core 2 Duo running at the same frequency, yet perform better in only a small number of applications. This makes them hard to recommend for most people, although it's encouraging to see that Intel is already releasing a batch of more affordable quad-core chips.
Click here for full details of the Intel Core 2 Quad family.
Author: James Gorbold
Intel Core 2 Quad