This may be a stupid question; however, I haven't come up with an answer via Google. I have two Toshiba Satellites (a Pentium M and a Core Duo). One has a 400 MHz bus and the other has a 533 MHz bus. I just upgraded the latter from 1 gig of ram (PC2-4200) to 2 gigs of ram. The P-M system is at 512 megs. I'm wondering, can I put this 533 MHz ram into the 400 MHz FSB system? Will the ram downclock to 400 MHz or is it incompatible? Many thanks for your time. -Hank
Hey, sorry for the wasted post. I thought all Pentium M machines used DDR2, but I just realized that my chipset only supports DDR. Guess I won't be sharing ram between these two machines after all. -Hank
If it were possible, yes, you can use faster RAM with a processor using a slower FSB. RAM is like a tire speed rating in that it's the maximum. A tire rated for 150MPH will run fine at 40MPH. The same is true with RAM. The MHz or PCxxxx rating is simply a means of indicating the fastest official speed the RAM is supported to go.
