DDR i DDR2 imaju i isti broj pinova (200). Dakle, jedina razlika je u poziciji utora na pločici.
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The 200-pin SO-DIMM has two variations for locating the notch which are nearly indistinguishable to the naked eye. If the notch is located further outboard, it indicates the DDR class of memory. When the notch is located nearer the center of the board, it indicates DDR2. These two types of memory are not interchangeable, and the different notch locations prevent incorrect installation. The 200-pin SO-DIMM depicted in the accompanying photograph has the notch slightly outboard, and is thus DDR. Caution should be exercised when visually identifying 200-pin SO-DIMM modules.