[scribus] Speed and CPU

[John Beardmore]

Jan Schrewe wrote:
> Am Freitag 12 Juni 2009 00:51:55 schrieb John Jason Jordan:

>> I changed the nice from 0 to 1 and it didn't make any difference.
> 
> I don't know what you do with your system, but unless it's a server there 
> shouldn't be going on much. So changing the priority does not gain anything. 
> The task scheduler uses the priority to decide which programm gets the next 
> CPU time slice. A high priority makes a difference under high load, but if 
> there is no competition for the CPU the programm that needs it, gets it.

This is a simplification.

Some kernels will slow the clock for low priority tasks. Folding at home 
for example seems to spawn a core running on my machine at 19. If I 
renice each of the cores to 0, the CPU speed on each core comes up from 
1300 MHz to 2600 MHz.


>>> You generally will find some program that is hogging resources and
>>> slowing down the others
>> The more I poke around the more I think the problem is that the CPU
>> speed is being throttled back by something in Linux. I looked in the
>> GUI for power management and found nothing. I don't understand why my
>> MHz applet stays at 800 even when Scribus is trying to do something
>> that must certainly be CPU intensive. I mean, occasionally it does go
>> to 2.0 GHz briefly, but usually it stays at 800 even when I am
>> patiently waiting for Scribus to do something.
> 
> Modern CPUs have a powersave feature that allows the kernel to reduce the 
> speed if no programm needs it.

Or if the ones that do are lower priority.


Cheers, J/.
-- 
John Beardmore, MSc EDM (Open), B.A. Chem (Oxon), CMIOSH, AIEMA, MEI
Managing Director, T4 Sustainability Limited. http://www.T4sLtd.co.uk/
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