[plug] SMP vs memory, was: *athon

[Mike Holland]

On Thu, 22 Jul 1999, Trevor Phillips wrote:

> > But doesnt timesharing do a similar thing? If Vmware is hogging the CPU,
> > other processes will be given priority and run fairly normally.
> 
> It's timesharing, except you have double the MHz to share amongst processes.
> So if you have ONE process thrashing, then it can thrash away on one CPU,

Yes, and I'm saying the thrashing process shouldnt affect the others,
_unless_it_is_swapping_. Think about it. When your PC appears to slow down
during a hevay background task, it is due to memory contention, not CPU.
(Or possibly poor scheduling.)
  I'm talking about a typical desktop case, with one CPU-bound process
at a time, and lots of other processes. In particular, you want the GUI to
respond quickly. The scheduler should give these light tasks all the CPU
they want, and the CPU-bound task gets all the spare CPU, say 98%, so a
 2nd CPU wont really help.
    Am i making any sense here ? Perhaps the difference is in our basic
assumptions of the load on the PC. Of course, a server is totally
different.

> leaving an entire other CPU free for the rest of the not-so-thrashing tasks.

So that is typically 95% idle, and the other process gains 5% ?


Mike Holland <mike at golden.wattle.id.au>            Perth, Australia.
                          --==--
	"Disraeli was pretty close: actually, there are Lies, Damn lies,
	 Statistics, Benchmarks, and Delivery dates."