Re: [Flightgear-devel] Multi core discussion

[Anders G. <and...@gi...>]

On Tue, 6 Jul 2010, fie...@zo... wrote:

> Op 06-07-10 14:12, Csaba Halász schreef:
>> I find it hard to believe that you have performance problems with a
>> core i7, assuming you got a halfway decent graphics card to go with
>> it.
>>
>
> I am not having performance problems. All is well, but I noticed that
> only one core thread is used while my Linux reports 8 available (4 cores
> times 2 threads).

Hi,

Have you tried telling OSG to use more threads?
Edit the following in your preferences.xml file:

   <rendering>
    <!-- Threading modes:
      AutomaticSelection
      DrawThreadPerContext
      CullDrawThreadPerContext
      CullThreadPerCameraDrawThreadPerContext
    -->
    <!-- multithreading-mode>AutomaticSelection</multithreading-mode -->
    ...
   </rendering>

Note that enabling concurrency here currently breaks the built in 
screenshot mechanism.

IMHO we need to proceed carefully with parallelization - to my 
knowledge there are only a few subsystems that use (or could with in 
reason be expected to use) enough CPU time to warrant the effort to move 
them into separate threads.

AFAIK the really big CPU time consumer is rendering. Various AI systems 
could be as well if they are used for a large number of AI entities 
(though computation of AI behaviour is probably still much cheaper than 
handling the 3d models for them).


Cheers,

Anders
-- 
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Anders Gidenstam
WWW: http://www.gidenstam.org/FlightGear/