Re: BAD CPU --> SIG11
Jan Kees Joosse (jankees@dutepp7.et.tudelft.nl)
Thu, 23 May 1996 09:49:01 +0000 (GMT)
In article <Pine.LNX.3.93.960512232530.407C-100000@jcoy-ppp.cscwc.pima.edu>,
"Jeff Coy Jr." <jcoy@jcoy-ppp.cscwc.pima.edu> writes:
>On Sun, 12 May 1996, lilo wrote:
>
>=> There are also known irregularities with L2 writeback cache and
>=> cleanroom-microcode AMD DX2/80's. I've never seen anything more than weird
>=> bogomips values though....
>=>
>i have a 486dx2-80, and the sig 11's only showed up for me when i really
>pushed the machine, like when i recompiled gcc. the first build would be
>fine, but the second build would crash about 45 minutes in. the crashes
>weren't really frequent, but setting the CPU speed back to 66mHz solved
>the problem and offered the fastest compile time.
>
>the only other solution was turning off the external cache, but without
>the extern cache, first stage gcc compile was 36 minutes at 80 mHz, but at
>66 mHz i get 26 minute first stage builds.
Take a look at http://www.bitwizard.nl/sig11/ This page describes
causes for a signal 11 while compiling (esp. kernel-compiles).
The effects of turning of the external cache also point to the direction
of memory subsystem problems. When you set the CPU speed to 80 MHz the
motherboard operates at 40Mhz, but when the CPU-clock is set to 66MHz the
board operates at 33MHz. Maybe slow memory? Check waitstages.
Jan Kees