Parallel Computer Architecture

430 CHAPTER 6 Snoop-Based Multiprocessor Design

Stride (bytes)

FIGURE 6.20 Read microbenchmark results for the Sun Enterprise. Each curve is for an array of

the size shown in the legend.

first look at application speedups and then at scaling, using only the SGI Challenge

for illustration.

Application Speedups

Figure 6.21 shows the speedups obtained on our six parallel programs for two data

set sizes each. We can see that the speedups are quite good for most of the programs,

with the exception of the Radix sorting kernel. Examining the breakdown of execu-

tion time for the sorting kernel shows that the vast majority of the time is spent

stalle ...