Cray Y-MP - Memory Board
The Y-MP is claimed to have been the first supercomputer to sustain over 1 gigaflop in application execution. An "M" model was equipped with slower but smaller DRAM that allowed it to house up to 32 GB of RAM.
NASA Ames Research Center
"Cray Y-MP - Memory Board." www.scxyhistory.org, Item #58 (accessed March 11 2014, 8:44 am)