Let's move on to the technical details of the processors and how to recognize the right model and stepping.

Core 2 Quad Q6600 (2.40 GHz)

Core 2 Duo E6750 (2.66 GHz)

The Core 2 Quad Q6600 with the Kentsfield core runs at 2.4 GHz on a 266 MHz FSB (1066 QDR). Its lower FSB gives it an advantage when overclocking, since the motherboard's Northbridge does not need to be able to reach extremely high clock speeds. The CPU consists of four cores, with two cores each sharing 4 MB of L2 cache. Theoretically, its power consumption is twice that of the Core 2 Duo, since it contains twice as many cores.

Intel's Core 2 Duo E6750 uses the Conroe core and runs at 2.66 GHz, which is slightly faster than the Q6600. The dual-core chip's FSB is also faster, which runs at 333 MHz (1333 QDR). This means that the motherboard has to deal with higher frequencies when the processor is overclocked. The CPU's two cores share 4 MB of L2 cache.

Buying The Right Model

The sSpec number in the product code

Not every shop gives you the processor's stepping version. In some cases, the sSpec number, which precisely identifies the processor, can also provide more information. If you buy the CPU in a brick-and-mortar store, the stepping version probably won't be stated, neither on the box nor on the processor itself. This is where the sSpec number comes in, which you can find at the end of the product code of the CPU's retail box.

The sSpec number on the CPU.

Our processors are unfortunately not very good examples, since they are both engineering samples that don't have sSpec numbers.