Lack of I/O performance is fast becoming a limiting factor in many com
puting systems. The yearly doubling of CPU speeds is not being matched
by corresponding gains in I/O performance. This paper explores one as
pect of the architecture of a high performance fault-tolerant cached R
AID subsystem for a multiprocessor. The disk write cache is implemente
d as a memory-mapped stable memory. The features of a VRAM-based stabl
e memory and its associated RAID controller are discussed.