High frame rates in Doom?

I've read about people playing Q3A at 1600x1200 at 250fps, and I don't understand how this is possible, because on my new computer, which has 3 gigahertz of processing power, 2 gigs of ram and the next to best video card, the framerate on GzDoom is usually 30fps or below at 1024x768, and will randomly slow down tremendously for a few seconds for no reason. Most of the time while I'm playing, there's also a large amount of fragements left over from the previous frame. I never had any of this happen on my dad's laptop, which is 75mhz and ran the original Doom at 30fps at almost all times. I honestly don't care if the framerate never reaches above 30, because 30 is plenty playable, but I find it curious that a near top of the line comoputer seems to struggle with a 12+ year old game at times.

GoatLord said:
but I find it curious that a near top of the line comoputer seems to struggle with a 12+ year old game at times.

The only way your machine could struggle with 12 year old games is if they access the hardware directly (like Doom does for sound.) Unlike Quake3, DOOM wasn't made with video acceleration in mind. GZDoom isn't old. If you want a faster GL-based engine try Risen3D or GLBoom (at least form my experience.)

Elaborating on what myk said, game companies can sometimes create poorly optimized game engines, which can be confusing on whether framerate of a game is a true test of the computer's ability to run fast. I don't think GZDoom is a poorly optimized engine (I assume you're not saying that either, as the OpenGl library is a safe base), because I have a AFX 3800, 1GB ram, and 6800u, and framerate never usually drops below 60, as well as in R3D and JDoom. Its probably some graphics settings or whatnot, as my comp slows down or doesn't run when vsync is enabled (6800 doesn't like it).

GoatLord said:
I've read about people playing Q3A at 1600x1200 at 250fps, and I don't understand how this is possible

Given Carmack and id's experience and mastery of creating new FPS game engines, QIII is probably one of the best optimized game engines of its kind; since it takes advantage of your hardware so well, thats why so it's used in so many benchmarks. Since the Doom 3 engine is the successor of the QIII engine, it's a great engine to test comp power, as far as OpenGL is concerned.

GoatLord said:

I've read about people playing Q3A at 1600x1200 at 250fps, and I don't understand how this is possible, because on my new computer, which has 3 gigahertz of processing power, 2 gigs of ram and the next to best video card, the framerate on GzDoom is usually 30fps or below at 1024x768,

In that case there's clearly something wrong with your system. With these specs you shouldn't have any problems whatsoever getting 200 fps or more. What kind of video card do you have? The only things that can create such extreme slowdowns are badly behaved background processes or hardware that doesn't support all the needed features.

I don't remember which one exactly, but it's one of the latest GeForces.

Best post your startup log. You get that with 'gzdoom +logfile log'.

Another information that could help me would be to enter 'stat rendertimes' in the console and than making a screenshot when the game is at 30 fps.