(16 MB) of main memory in 16 banks, respectively. The main memory was built from 4 Kbit bipolar SRAM ICs. CMOS memory versions of the Cray-1M were renamed Cray X-MP/1s. This configuration was first used for Cray Research's UNIX port.

In 1984, improved models of the X-MP were announced, consisting of one, two, and four-processor systems with 4 and 8 million word configurations. The top-end system was the X-MP/48, which contained four CPUs with a theoretical peak system performance of over 800 MFLOPS and 8 million words of memory.