(Rambus DRAM) Pronounced "r-d-ram." A dynamic RAM chip technology from Rambus, Inc., Los Altos, CA (www.rambus.com). Rambus licensed its memory designs to semiconductor companies, which manufactured the chips. In 1995, Base RDRAM was introduced with speeds up to 600 MBytes/sec. In 1997, Concurrent RDRAM increased speed to 700 MBps, and Direct RDRAM boosted speed to 1.6 GBps in 1998. Concurrent RDRAMs have been used in video games, while Direct RDRAMs have been used in computers.

Direct RDRAM chips can also be built with dual channels, doubling the transfer rate to 3.2 GBps. Intel was the major promoter of the Direct RDRAM technology.

Metal-Covered Modules
The Direct RDRAM chips used in computers were housed in Rambus Inline Memory Modules (RIMMs) that had a metal cover. RIMMs had different pin settings and were not interchangeable with DIMMs and SDRAM. See dynamic RAM, SLDRAM and memory modules.