Models for Parallel Processing WIthin Programs:
Application to CPU:I/O and I/O:I/O Overlap
Approximate queueing models for internal parallel
processing by individual programs in a multiprogrammed 
system are developed in this paper.  The solution technique
is developed by network decomposition.  The 
models are formulated in terms of CPU:I/O and I/O:I/O overlap
and applied to the analysis of these problems. 
 The percentage performance improvement from CPU:I/O
overlap is found to be greatest for systems which 
are in approximate CPU:I/O utilization balance and for
low degrees of multiprogramming.  The percentage 
improvement from I/O:I/O overlap is found to be greatest
for systemtems in which the I/O system is more 
utilized than the CPU.
CACM October, 1978
Towsley, D.
Chandy, K.M.
Browne, J.C.
