No, you're just being obnoxious. Give it a rest, will ya?
Well he did give the wrong answer to the question. The title of the thread is:
"Which is better for 3d acceleration"
I have yet to see any better solution for 3d in linux then nvidias. It is on par with their windows drivers for performance, it handles all the modern openGL levels, it is just as reliable (if not more) then any of the open source drivers. Because of it's superior performance it is also more efficient.
Nvidia makes a decent closed-source driver which breaks things regularly (recently: vim, kde, suspend&resume), but is still remarkably stable, considering that they totally replace half of your distribution with their own proprietary stuff. They are fast to support new kernels, and many people are happy with them. They don't support modern X technologies such as xrandr, or proper framebuffers and modesetting because it's essentially a repackaged Windows driver.
AMD offers an OK closed driver, which is fast, but has nagging issues that people complain about. It's more fussy than the nvidia one, and does not support new kernels in a timely fashion.
AMD also funds open-source development, releases virtually all docs they are allowed to release, helps volunteer Mesa and X developers with driver development. They have excellent and full-featured open source drivers for older cards, and decent drivers for all newer hardware. You get OpenGL 2.1, excellent 2D and video playback, the drivers are very stable, but 3d is still nowhere near as fast as the blobs.
The short and 99% correct answer is that people who support open source and open documentation buy AMD, while people who don't care about these things buy Nvidia.
How do these cards compare for 3 acceleration? (in linux of course)
Also is there any significant performance difference between Ubuntu and Fedora (using the same drivers)? and for 3d in general (regardless of brand/video card)?
There shouldn't be much difference between ubuntu & fedora, assuming the same basic setup from each. I haven't actually used fedora, but I have looked at ubuntu and gentoo - for 3d there wasn't much difference, and for everything else....well it doesn't belong in this thread.
Drivers for each card will have bugs, but for native 3D apps, it really shouldn't matter these days; you don't really hear of anyone having major issues with native 3D apps (I refer to standalone programs, not window managers). I guess it depends on your definition of "3d in general", and how long you'll want the cards to last (newer drivers from each will fix bugs, there's the issue of if you want open source drivers, if you need OpenGL 3/4, power management, card price, etc).
When reading through the forums, ignore anything saying "this is crap, that's better" without giving reasons. Sadly there's an awful lot of people saying one is better than the other but giving no particular reasons as to why. So look at actual problems, make a pros & cons list, and then enjoy shiny new hardware.