[plug] SMP vs memory, was: *athon

[John Summerfield]

> On Thu, 22 Jul 1999, Trevor Phillips wrote:
> 
> > Two CPU's would mean VMWare could have a whole CPU to itself, and normal Li
> nux
> > apps can use the other (roughly speaking), as opposed to everything tusslin
> g
> > for CPU time on one CPU...
> 
> But doesnt timesharing do a similar thing? If Vmware is hogging the CPU,

Timesharing is something else ... reflects the use of one computer bu more 
than one logged-in user. We're talking about multitasking (separate 
threads/processes).

> other processes will be given priority and run fairly normally.
>   If the "whole PC" seems to slow down, it would be because of memory
> swapping, not the CPU. So a second CPU wont help much, right?
>  Just get more memory.
> I expect you'll only really benefit from a 2nd CPU if 2 or more processes
> are simultaneously hogging the CPU.
>   (of course multi-threading is a separate issue)

Multiple CPUs will help when there are several tasks contending for the 
CPU: loadaverage > 1 for a significant proportion of the time. Like emu 
(one of my comouters) was a few days ago_ loadaverage > 4 for several days.


You can get many of the advantages with a beowulf cluster: see the 
relevant howto for more info.



-- 
Cheers
John Summerfield
http://os2.ami.com.au/os2/ for OS/2 support.
Configuration, networking, combined IBM ftpsites index.