A high bandwidth DRAM, designed by Rambus, Inc. of Mountain View, CA.

RDRAM is used mainly for video accelerators, and also in the Ultra 64 from Nintendo. It offers sustained transfer rates of around 1000 Mbps, compared to 200 Mbps for ordinary DRAM. Although it cannot be used as a direct replacement for existing memory, it is likely that it will replace DRAM and SDRAM as the main memory system in personal computers as the bus speeds required by these machines increase. SDRAM can operate up to around 100MHz, but RDRAM has been demonstrated by the manufacturers running at 600MHz.

The memory is also only 8 or 9 bits wide, so the bandwidth would increase enormously if it were used in parallel to give 32 or 64-bit memory.