mf@ircam.ircam.fr (Michel Fingerhut) (09/26/90)
We noticed a significant slow-down of our 5820 (bi-processor 5800) in response time after upgrading from Ultrix 3.1 (which supports a single processor) to Ultrix 4.0 (whose "kernel has been enhanced to support multiple processors executing kernel code"). The local DEC support's reply to my call was that it was a known "problem" and their advice was to turn off the 2nd CPU until a fix is found. I did this, and lo and behold, "ls" runs so much faster... I wonder if by turning the remaining CPU off I'll get the computing power DEC claims for the DS5820.
rosenblg@cmcl2.NYU.EDU (Gary J. Rosenblum) (09/27/90)
I haven't had that problem on my 5820 with Ultrix 4.0. I timed an ls in a HUGE directory with both cpu's on, and then with one off, and the times were comparable. Did the DEC people give you any indication as to the problem (or a patch to 4.0?) Gary
ndoduc@framentec.fr (Nhuan Doduc) (09/27/90)
In <1990Sep26.151338.14480@ircam.ircam.fr> mf@ircam.ircam.fr (Michel Fingerhut) writes: >.... >I did this, and lo and behold, "ls" runs so much faster... I wonder if by >turning the remaining CPU off I'll get the computing power DEC claims for >the DS5820. You have 2 proc. you shut off 1 and get (my interpretation) twice (faster) My deduction is that if you shut down the remaining then the computing power would be infinitely faster. Hey look at this: 1 / half = twice 1 / zero = infinity CQFD --nh Nhuan DODUC, Framentec-Cognitech, Paris, France, ndoduc@framentec.fr or ndoduc@cognitech.fr, Association Francaise des Utilisateurs d'Unix, France, doduc@afuu.fr