Meothuru <nomail@nomail> wrote:
> A normal user have only a limited bandwith of CPU-power and this is far
> away from 100% CPU power.

  Far away? Not really.

  If nothing CPU-intensive is running at the same time, a CPU-intensive
program (such as POV-Ray) will get almost 100% (usually from 99% upwards).
  The OS doesn't need almost any CPU at all for task switching, and if
there isn't anything else using the CPU heavily, then there's nothing
which would require it.

> Because a program/user wich gets realy 100% of
> the  CPU power would block the computer for all other programs/users.

  He said "nearly 100%". That is, not exactly 100%, but a bit lower,
like 99.5%, which by all practical purposes is the same thing.

> And this can not be allowed in a Multiuser-System.

  I think you misunderstand. POV-Ray takes all the CPU time which is
unused. If nothing else is using the CPU, then it takes all of it.
  That doesn't mean that if another CPU-intensive program is started
it would not get its share.

> You can verify this very simple. Go to the "root-mode" and start
> provray with the highest possible "nice value" of the privileged mode.
> In this mode povray gets *much more* CPU-power than a normal user can
> ever get....

  Much more? I would need to see some evidence before I believe that.

-- 
                                                          - Warp

Post a reply to this message