Report Number: CS-TR-86-1119
Institution: Stanford University, Department of Computer Science
Title: Simulation of an Ultracomputer with Several 'Hot Spots'
Author: Rosenblum, David S.
Author: Mayr, Ernst W.
Date: June 1986
Abstract: This report describes the design and results of a time-driven
simulation of an Ultracomputer-like multiprocessor in the
presence of several "hot spots," or memory modules which are
frequent targets of requests. Such hot spots exist during
execution of parallel programs in which the several threads
of control synchronize through manipulation of a small number
of shared variables. The simulated system is comprised of N
processing elements (PEs) and N shared memory modules
connected by an N x N buffered, packet-switched Omega
The simulator was designed to accept a wide variety of system
configurations to enable observation of many different
characteristics of the system behavior. We present the
results of four experiments: (1) General simulation of
several 16-PE configurations, (2) General simulation of
several 512-PE configurations, (3) Determination of critical
queue lengths as a function of request rate (512 PEs) and (4)
Determination of the effect of hot spot spacing on system
performance (512 PEs).