Intel Core 2 Extreme QX6700 (Kentsfield Quad Core) - Intel Core 2 Extreme QX6700


The chip we were sent, was the Core 2 Extreme QX6700. This is basically two Core 2 Duo E6700 processors on the same package. Each core runs at 2.66GHz, with each pair of cores sharing 4MB of cache. Being an Extreme Edition, unlike the E6700, it is fully multiplier unlocked. I didn’t do any overclocking myself, unlike our sister publication, Bit-Tech but what I can say is, the more cores you have, the lower your chances of a high overclock. All you have to do is have one core that can’t quite cut the mustard and that will cripple your overclocking ability. What is worth noting, is that it was running exceptionally cool considering there were four cores, at around 15 degrees above ambient.

For testing this chip, I took our SpodeMark2D suite, which was coded for our Core 2 Duo launch and compared to a Core 2 Duo E6700 and a Core 2 Extreme X6800. I did however, adjust the coding slightly, to use four threads instead of two. SpodeMark2D performs every day tasks, such as adjusting photos in Photoshop Elements, encoding video using XviD, encoding and decoding MP3 audio and file compression and decompression. You can read all about this in the original article.

Quad processors and higher have been around for a while, so there is nothing new here. And a lot of software, once designed to be multi-threaded, will be compatible with two, four or more processing units. However, it is worth remembering that as you add more processors, you also get diminishing returns.

Our results where particularly disappointing. In single tasks, the most increase in speed we saw, was by 15 per cent, when compressing a large file. In multiple tasks, there was a 20 per cent increase in speed.

Considering processing power has doubled, we should be seeing more scaling than this. The likely scenario, is that these particular (and I might add – typical) applications just don’t take advantage of four cores properly yet. What is most surprising, is XviD, which scales very well from one to two cores, doesn’t scale well from two to four. Perhaps other encoders will have better performance.

Interestingly, in audio encoding/encoding, the Core 2 Duo E6700 was sometimes faster. This suggests that either the coding is not particularly equipped to handle four cores, or that there was latency introduced in cross-communication through the North Bridge.

When comparing to the Core 2 Extreme X6800, which is similarly priced, we can see that for most cases, you are better off going for higher clocked dual-core, than you are for quad-core at a lower speed.


Extra two cores aside, there is nothing new on display here. This is the same Core 2 technology, just put together in a neat package. Very few people will need quad cores, as demonstrated by our results, but also through pure common sense. With DirectX 10 removing even more CPU overheard, as a gamer, one has to question the need for four cores right now. However, it’s here, and it works as well as current software allows. So for anyone who wants the very best, look no further. Considering what you’re getting, the price isn’t actually too bad either!