Does any DDR RAM work (but run slow) if used in an older machine?

[davejm]

We're in the process of looking to upgrade the RAM in some PC's here at work. They are currently running either PC2100 (133mhz) or PC3200 (200mhz).

I'm guessing if we order PC3200 RAM, it will work in both machines? i.e that it'll just run slow in the machines that don't support the faster RAM?

 

[davejm]

Cool... I was sure that was the case, I just wanted to double check as we'll be ordering a fair few.

Aye, I wouldn't be silly enough to order DDR2 for DD1 machines!