•COMA: cache-only memory architecture
–Data migrates into local DRAM of CPUs where it is being used
–Handles very large working sets cleanly
–Replacement from DRAM is messy: have to make sure someone
still has a copy
–Scope for interesting OS/architecture hybrid
–System slows down if total memory requirement approaches RAM available, since space for replication is reduced
•Examples: DDM, KSR-1/2, rumours from IBM…