Horde3D

Hi,

I've noticed a sudden performance drop in the chicago sample - I get a constant 60fps, until enough characters are on screen and then I get constant 30fps. There is no middle ground, just 30fps or 60fps.

This occurs no matter how close to the characters I set the camera.

I'm on a 3ghz p4 with a 7900GT card.

I'm looking at using Horde for a small game with a bunch of swarming characters (I spent some time doing this with Panda3D before discovering Horde was being written for my situation!)
Just curious as to what might cause the 50% slow down, or how I can find out what the bottleneck is.

That sounds like a V-sync issue to me. V-sync ensures that the frame rate exactly coincides with your monitors refresh rate (to avoid drawing a frame part-way through a screen refresh).


For example, with v-synch enabled, if your monitor is running at 60hz, then the fps will never be higher than 60fps (the graphics driver will intentionally cause a slow down to stop it going faster than 60).

If the frame rate drops below 60fps (1 frame for each screen refresh), then the driver will intentionally cause a slow down to limit the frame rate to half of 60hz, which is 30fps (1 frame every 2 screen refreshes). If the frame rate drops below 30fps, then the driver will limit it to 15fps (1 frame every 4 screen refreshes), etc...


I don't think Horde3D currently has a function to turn V-sync on or off, but you can usually force it on and off (for testing) in the advanced section of your display properties control panel.