I'm seeing a performance problem I don't understand.  I'm Doing benchmarks to 
compare a DEC alphastation 600 5/266 to an SGI R8000 Power Indigi 2.  
It's a wonderful box by the way!  The DEC is looking very good,
but in some fairly repeatable circumstances, it goes to pot. Vmstat will
show it running along at 99% cpu in user mode and suddenly that drops down to
1-5 %, with over 90% idle.  The cpu looks like it is in never never land.  At 
this point, the mouse and keyboard are frozen, and nothing I do there works,
 although I have a vt220 with the vmstat running, an it updates normally.  
I was shading a proE model once when this happened, and the partially 
shaded model (an 88MB model, quite large, with about 500 MB out of 1.2GB 
of swap used) just hung on the screen for about 2 minutes, then it 
snapped back to life and resumed as though nothing had happened.
The system is loaded with 256MB of memory, although it is swapping 
extensively, and when the "freeze" occurs, there are only about 20 
pages of free memory.  Anyone got any ideas what is happenning?  
It's killing the machine in the benchmarks.
Stan Huhman
John Deere PEC
Waterloo, Iowa
Received on Wed Jul 19 1995 - 18:48:17 NZST