A new approach micro benchmarks, has recently been develop. using theis technique, we have analyzed the KSR1. and in particular the ALLCACHE memory architecture and ring interconncection. Wi have been able to elucidate many facets of memory performance. The technique has enabled us to identify and characterize parts of the memory design not described by Kendall square research. Our results show that a miss in the local cache can incur a penalty ranging from 7.5 microseconds to 500 microsenconds (when a dirty "page" in the local cache must be evicted). The programmer must be very carefull in placement and accessing of data to obtain miximum performance from the KSRI: the data presented here will help in understanding the performance actually obtained.