Erratic Framerates - OpenGL, Linux, P4

An SDL/OpenGL app I’m working on is displaying some really erratic framerates on one of the boxes I’ve tested it on. Most of the boxes I’ve tested (see below) have pretty smooth framerates, but the Dell box running RedHat is really erratic. More specifically, if the average framerate is about 90 fps on the Dell, I get about one frame in 10 or 20 with an interframe delay equivalent to about 20 fps. Even though my simulation code does NOT rely on consistent frame time intervals, this jittering produces noticeable effects.

Anyone have any ideas as to what the problem might be? This is a Dell Dimension 4500, 2.4Ghz P4, 512MB RAM, ATI Rage 128 Pro Ultra running RedHat 9.0 (no Windows installed at the moment, though I’m trying to scrounge a spare drive to install/test that angle).


p.s. Sample systems are just about anything I can lay my hands on for a few minutes, including:

  • 400 MHz G3 Powerbook running MacOS 9 or Mandrake
  • K62-500 running RedHat
  • 1.2 GHz Duron running RedHat or Windows