Are all DDR2 memories interchangeable

No, not all DDR2 memories are interchangeable. While DDR2 memory modules share the same general specifications, they can vary in terms of speed (measured in MHz), timings, and voltage requirements. Additionally, motherboards have specific compatibility requirements, so it's essential to check if the motherboard supports the particular DDR2 module you intend to use. Mixing different speeds or timings may lead to instability or reduced performance.