Strange framerates....

[mk]

I created a 3D program and wanted to test the fps in it and so I made a routine that calculated the fps but I was getting strange results. My slower computer with worse video card was getting much higher frames per second so I commented everything out of the program except the text to display the fps and it still had the same result. Finally, I added the fps calculation to one of Nehe's tutorials which just displays some text (http://nehe.gamedev.net/tutorials/lesson13.asp) and i get these results:
PII 450 (128 RAM) with ATI Rage Fury 128 32MB - 190fps
PIII 866 (512 RAM) with GeForce 2 GTS 64 MB- 95fps
PIII 733 (1GB RAM) with GeForce 256 32MB - 60fps
these were 640x480 windowed mode but i got similar results in full screen and under different resolutions.
In other OpenGL apps the two PIIIs perform much better than the PII.
here is my fps code:
QueryPerformanceCounter(&time);
if(starttime==0)
{
starttime = time.LowPart;
framecount = 0;
}
framecount++;
endtime = time.LowPart;
elapsed = endtime-starttime;
if(elapsed>=100000) //delay display of fps so it is readable
{
QueryPerformanceFrequency(&freq);
fps = ((float)framecount/(float)(elapsed))*freq.LowPart;
framecount = 0; //restart calculating again
starttime = time.LowPart;
}
any ideas on what the problem is?

You can check the settings of the cards sync, ...

[mk]

I turned off full scene anti aliasing and made vertical sync always off and my GeForce 2 computer speeds up to 1100 fps. Thanks man.

[T2k]

don´t use debug mode !!!