You can use the DOCP timings at lower speeds yes. A little performance difference yes. Faster is better. If you don't use all 16GB now, then save your money and just use what you have at higher speeds.
You can use the DOCP timings at lower speeds yes. A little performance difference yes. Faster is better. If you don't use all 16GB now, then save your money and just use what you have at higher speeds.