jongew is right. The 2 systems may should be compared. But I think glxgears is basically influenced in its performance by GPU. So this could give at least an estimation where framerate should be!
I also forgot to post information about the laptop I mentoined. It is an Intel PIII, 1 GHz. The GPU says it can do FW bit they are actually unused:
Fast Writes: Disabled
I am watching performance values from this group since some days and see that Athlon based systems (especially those with nforce2 chipsets) have a performace that is about 80% less (I mean factor 1.8 more FPS) than expected. Since I have no experience with Geforce4 GPUs I took as reference
Here you can see that a GeForce4 should run at up to 7000 FPS. For a GeForce2 I would expect about 1500FPS.
The GeForce2 values I compared came from different sources, most friends of mine.
All in all there seem to be less performance problems with intel based systems.
I can try to enable FW and / or SBA tonight when I am at home again. Perhaps it is a solution for me.