Question: can ddr3 fit in ddr2?
Answer: 2 Answers. no - DDR2 and DDR3 are not compatible nor interchangeable. aside from electrical differences (voltage, signal timing etc) the SO-DIMM modules should be keyed differently, additionally I think DDR2 SO-DIMMs are 200 pin whereas DDR3 are 204 pin, they shouldn't fit in same slots.