RIMM is not an acronym and is a trademark of Rambus incorporated for the Direct RDRAM (Rambus or DRAM) modules. RIMM is computer memory that resembles DIMMs; however, it is 184-pin and is available with built-in ECC support and Non-ECC at speeds up to 800 MHz. RIMM modules are commonly used on the Intel Pentium 4 motherboards.
Unlike most other computer memory, computers that support RIMM require a continuous signal. If a memory socket is left empty, the computer will not work properly. Therefore, users must utilize C-RIMM modules in any slots that do not have RIMM modules.
SO-RIMM is a 160-pin module and is Rambus memory used in laptop computers.
Note: RIMM is NOT short for Rambus In-line Memory Module.