CRIMM

CRIMMs are "Continuity Rambus In-Line Memory Modules". CRIMMs are passive devices used on motherboards that help to enable a Rambus system to terminate properly. The design of many common Rambus memory controllers dictates that memory sticks be installed in sets of two. Any remaining open memory slots must be filled with CRIMMs. CRIMMs appear physically similar to regular memory sticks except they do not have memory modules soldered on them.

The only x86 processors to support use of Rambus memory and therefore need CRIMMs were slot 1 Intel Pentium III desktops, along with socket 423 and socket 478 Intel Pentium 4 processors. Intel had many problems implementing Rambus memory in these processors, which encouraged rival chipmaker AMD to scrap plans to support Rambus in its Athlon series of processors.

A single RIMM RAM stick usually makes a complete bank, but unused RIMM sockets can't be left empty. Instead, use a special RIMM terminator, called a continuity RIMM (CRIMM) stick, to fill any unpopulated RIMM sockets.