Um, No.
Rambus memory works totally different and the notches in SDR SDRAM, DDR SDRAM and RDRAM are different.
And you need to buy RDRAM in pairs. RDRAM Picture DDR RAM Picture
I have RDRAM and I hate it. After 2 years two of the RDRAM chips I have failed on me, plus they are way more expensive than most other types of RAM, and they are much harder to find.
Only plus is the have good all around performance.