Is a DDR3 MB compatible with DDR2 RAM?

Question

If a motherboard's specifications say it supports DDR3 SDRAM sticks, would I be correct to assume it is also compatible with DDR2 RAM? Am I wrong, or does it depend on the motherboard?

Answer 1

No. DDR3 and DDR2 are designed differently. Both have different key placing so they won't even physically fit, not to mention differences in electrical voltage:

There are motherboards which will provide entirely separate slots for DDR2, but you cannot use DDR3 in DDR2 slots, or both types together.

Answer 2

Supports DDR3 SDRAM sticks, would I be correct to assume it is also compatible with DDR2 RAM?

That's incorrect. DDR3 Rams are PIN & voltage incompatible.

Or does it depend on the motherboard?

Certain motherboards provide DDR2 & DDR3 slots, but you can use only 1 type at a time, you cannot mix and match both