Epson 256MB SDRAM 168-pin DIMM for Lasers for Epson C1100,C2600,C3000,CX11N,CX21N,N2550 Printers. DIMM is a type of circuit board that holds memory chips. DIMMs have a 64-bit path because of the Pentium Processor requirements. Because of the new bit path, DIMMs can be installed one at a time, unlike SIMMs which on a Pentium would require two to be added. In late 1996, SDRAM began to appear in systems. Unlike previous technologies, SDRAM is designed to synchronize itself with the timing of the CPU. This enables the memory controller to know the exact clock cycle when the requested data will be ready, so the CPU no longer has to wait between memory accesses. SDRAM chips also take advantage of interleaving and burst mode functions, which make memory retrieval even faster. SDRAM modules come in several different speeds so as to synchronize to the clock speeds of the systems they'll be used in.