During last IDF we had the chance of making a short review on Intel’s first quad-core CPU, Core 2 Extreme QX6700 (codenamed Kentsfield) – which runs at 2.66 GHz. This time we got one sample from Intel and were able to run several programs and compare its performance with other CPUs from Intel and from AMD. Does quad-core CPUs really improve PC performance? Check it out.

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Figure 1: Core 2 Extreme QX6700 engineering sample.

We have already written a full article on how Intel’s quad-core technology works. We recommend you to read this article before going further.

As mentioned, Core 2 Extreme QX6700 has four cores and runs internally at 2.66 GHz. As you can see the only difference on its name is the letter “Q”, standing for quad-core. Newer quad-core CPUs to be released in the beginning of 2007 will be called Core 2 Quad.

Internally this CPU has two Core 2 Duo chips. So you can think of Core 2 Extreme QX6700 as being two Core 2 Duo E6700 chips. Since it has two separated chips inside, its 8 MB L2 memory cache isn’t unified as it occurs with Core 2 Duo processors. In fact it has two 4 MB L2 memory caches, the first one is shared by cores 1 and 2 and the second one is shared by cores 3 and 4.

Externally it keeps using socket 775 and 1,066 MHz front side bus (FSB), so you can install Core 2 Extreme QX6700 on any socket 775 motherboard that supports Core 2 Duo CPUs (however a BIOS upgrade may be necessary).

The system recognizes Core 2 Extreme QX6700 as four independent CPUs. Keep in mind that each CPU core is a real physical CPU and not a simulation like HyperThreading technology. By the way, Core 2 CPUs don’t have HyperThreading technology; this technology – at least so far – is exclusive of NetBurst microarchitecture, which is used by Pentium 4 and Pentium D (dual-core version of Pentium 4) processors. Core 2 CPUs use a new microarchitecture, called Core microarchitecture, which is based on Pentium M’s (which, in turn, is based on Pentium III’s).

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Figure 2: Windows correctly recognizes Core 2 Extreme QX6700 as four CPUs.

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Figure 3: Four CPUs available on task manager.

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Figure 4: All Core 2 Extreme QX6700 specs on CPU-Z.