[comp.benchmarks] bad mini-benchmark

karplus@ararat.ucsc.edu (Kevin Karplus) (11/30/90)

The "benchmark"
	echo 2^5000/2^5000 | /bin/time bc
seems to have poor predictive power for other applications.

Here are results on different Suns (all diskless workstations with at
least 8Mbytes of RAM): 
	Sparcstation SLC	44.5 real	43.4 user	0.1 sys
	3/80			33.3 real	28.7 user	1.0 sys
	4/110			26.8 real	26.3 user	0.1 sys
	Sparcstation 1+		12.2 real	12.0 user	0.1 sys

Note that the 3/80 appears faster than the Sparcstation SLC!  Having
used both machines for months, I can assure you that the SLC is easily
a factor of two or three faster on most applications (except
compilation and linking, which are I/O bound on my diskless SLC).

Does anyone have an explanation for the unexpectedly poor performance
of the SLC on this trivial benchmark?
All three of the Sparc-based machines were running the same copy of
"bc", so it isn't a difference in compilation.

Kevin Karplus

zeeff@b-tech.ann-arbor.mi.us (Jon Zeeff) (12/02/90)

Anyone know why a Sun 3/50 is so much slower than a 3/60?
-- 
Jon Zeeff (NIC handle JZ)	 zeeff@b-tech.ann-arbor.mi.us