gnu@hoptoad.uucp (John Gilmore) (03/25/88)
barnett@vdsvax.steinmetz.ge.com (Bruce G. Barnett) says:
> I still don't understand how one Sun 3/50 can be 40% faster than another.
Curiously enough, the video display eats about 40% of the memory
bandwidth -- unless you turn it off (/usr/bin/screenblank). Then it
goes down into the noise (just enough to refresh RAM). Without the
video on, a 3/50 is about the same speed as a 3/160. Perhaps the
benchmark was run "over the net" on a screen-blanked machine?
--
{pyramid,ptsfa,amdahl,sun,ihnp4}!hoptoad!gnu gnu@toad.com
"Watch me change my world..." -- Liquid Theatrecrowl@cs.rochester.edu (Lawrence Crowl) (03/26/88)
In article <4238@hoptoad.uucp> gnu@hoptoad.uucp (John Gilmore) writes: >barnett@vdsvax.steinmetz.ge.com (Bruce G. Barnett) says: >> I still don't understand how one Sun 3/50 can be 40% faster than another. > >Curiously enough, the video display eats about 40% of the memory bandwidth -- >unless you turn it off (/usr/bin/screenblank). Then it goes down into the >noise (just enough to refresh RAM). ... Perhaps the benchmark was run "over >the net" on a screen-blanked machine? I did just such a benchmark. Here are the Dhrystone numbers: SunOS, cc, pc C (noreg) C (reg) Pascal Sun 3/50 on console 2267.0 (1.00) 2517.5 (1.00) 2486.3 (1.00) with video display on Sun 3/50 via rlogin 2898.6 (1.28) 3180.2 (1.26) 3231.7 (1.30) with video display off So turning the display off yields a (relatively) consistent 28% speedup. -- Lawrence Crowl 716-275-9499 University of Rochester crowl@cs.rochester.edu Computer Science Department ...!{allegra,decvax,rutgers}!rochester!crowl Rochester, New York, 14627