Oops... I slowly become to think that this is a featuer and not a Problem!
The GF4 MX440 has a GPU Clock of 270Mhz and a Memory Clock of 400!
The GFX 5200 has GPU 250 and Memory 280.
I tweaked the clock settings of my GFX with nvclock to 270/400 Mhz (does this
glxgears 500 -> 1000FPS
Quake 50 -> 80FPS
Still not as good as the GF4. Maybe there is a problem with the Fedora Kernel and
the GFX driver ?