The Core 2 Duo Processor Family
If you are looking for details on Intel's Core 2 microarchitecture, please have a look at our IDF Spring 2006 article: Will Intel's Core Architecture Close the Technology Gap? - it includes the details of the architecture. Our Core 2 Duo launch article Game Over? Core 2 Duo Knocks Out Athlon 64 provides additional information that you'll want to read about as well.
Although the Core 2 Extreme X6800 top model and its quad core counterpart, the QX6700, clearly are the best performing processors today, we don't think it's necessary to spend the $999. Let's look at the other models instead, as the whole processor portfolio is interesting. There are four regular Core 2 Duo versions, namely the E6300, E6400, E6600 and E6700, covering the area between 1.83 GHz and 2.66 GHz. All of these require a current motherboard that supports FSB1066 system speed. The two entry-level versions, the E6300 and E6400, carry only 2 MB of level 2 cache, while all other models have a whopping 4 MB cache. The more cache, the better, because both cores share the entire cache area dynamically to hold data and to work on it efficiently.
You will notice that processor prices increase dramatically as you approach the higher-end versions: as always, there is a large price premium for the last mile of performance. From this point of view, overclocking clearly makes sense, as you aim at running an ordinary processor model at speeds that would cost you many more hard-earned dollars.
Why Core 2 For Overclocking?
Purchasing a processor with overclocking in mind always requires a reasonable product choice to start with. Then, you need hardware that is suitable for overclocking and, eventually, a little luck. Although all processors in a given family come from the same manufacturing facilities and thus should all be capable of reaching about the same maximum clock speed, there are individual differences in each processor that even the tightest manufacturing tolerances cannot control completely. Some people buy an entry-level Core 2 Duo E6300 and assume that it should be able to run at the clock speed of the top model. This usually is the case, but not always.
Here comes the nice part: we learned from the Intel's NetBurst past that its 65 nm silicon is capable of enduring somewhat higher core temperatures. Think of the Pentium Extreme Edition 840 90 nm 3.2 GHz dual core as an example. The 65 W Thermal Design Point (TDP) of Core 2 Duo should thus not be the processor's limit, but rather Intel's self-imposed thermal envelope. The 2.93 GHz Extreme Edition proves that the limit can be stretched, if necessary, as this chip is rated at 75 W maximum power draw, which it naturally requires at its increased clock speed (double the clock speed quadruples the power requirements at the same voltage.)
Following this logic, an entry-level Core 2 processor at 1.83 GHz stays far away from the 65 W maximum, giving the user a broad overclocking range. Now if only there weren't the limited multiplier...
