This may be a dumb question, but here goes…
I know that OpenGL is platform-independent (except for the GUI package aspect) but what i’m wondering is, what kind of dependecies are there in the performance of an OpenGL implementation? i.e. what could cause a particular OGL implementation to run faster/slower on different machines/operating sys’s?
The big dependices is
- video card
- proccessor speed
- other hardware (memory, AGP, …)
Some computers have totally different architectures like PC&Mac vs SGI and because of that different limitations.
I do not think that it depends much on the OS itself but the most popular will propably be most optimized.
A minor(?) difference is how much the implementation is allowed to change. On linux can everything be done. If nvidia wants to do the same on Windows would they have to ask: “Hey Bill, we are replacing opengl32.dll and put some new stuff in the kernel. OK?” 
thanks for your reply…after some more extensive searching, i found some good information right here on this site, under the FAQ/technical/performance section…
http://www.opengl.org/developers/faqs/technical/performance.htm
u basically said the same thing…thanks again 
mandy