[ODE] Performance question

STenyaK (Bruno Gonzalez) stenyak at gmx.net
Thu Sep 14 18:15:03 MST 2006

On Fri, 15 Sep 2006 02:52:23 +0200, Jon Watte (ODE)  
<hplus-ode at mindcontrol.org> wrote:

> Is this in release mode or debug mode?
Debug mode.
> Are you using floats or doubles?
> How big is your step size?
Doesn't matter for this problem (the problem happens indepndently of step  
size), but i'm currently running physics at 300Hz.
> Do you empty your contact joint group every step? (doesn't hurt to ask)
> On what kind of client hardware?
Amd Sempron 2Ghz + 512kb L2, 512megs of ram (no swapping is needed at any  
time during simulation), on a gentoo linux 2.6.16 or so. No other apps are  
taking the cpu. It's been reported to also happen in windowsXP + msvc, and  
to also be solved by replacing all suspension physics with hinge2 joints.
> If you run a profiler on the program while it's getting 1-4 fps, where  
> does it say you're spending your time?
Running a profiler takes too much cpu time (simulation can't run realtime,  
so graphics are not rendered anymore, and there are more side effects), so  
i profile the important parts myself, using SDL timers (which give a  
precission of msecs). The slowdown is definitely due to ODE (which takes  
up to 95% of total app time, but usually 40-50%), but the timing is too  
little precise to know if the problem is collision detection or the solver  
(i get an average of 50% time of the sum spent on each of them, so i dunno  
what to think about it).


Site:   http://1ksurvivor.homeip.net  <1kSurvivor>
         http://motorsport-sim.org     <Motorsport>
         http://kwh.iespana.es         <KuantikalWareHouse>
         http://emuletutorial.info     <EmuleTutorial>
ICQ:    153709484
Mail:   stenyak AT gmail DOT net

More information about the ODE mailing list