The performance of concurrent computers depends fundamentally on the capabititiesof the individual processing nodesand the characteristics of the interprocessor communication system. The Intel iPSC”/Z is significantly better in both cate ories than the original iPSC (iPSC/l). This paper will briefly compare the 4 ardware of the two machines and then discuss the actual measured performance improvement of several kernels of application codes. The improvements vary from a factor of two
and a half to more than a factor of 30.