finally i could fix it!!!!
using suse ati drivers instead ati officials
now i get:
> glxgears
24227 frames in 5.0 seconds = 4845.400 FPS
25683 frames in 5.0 seconds = 5136.600 FPS
25684 frames in 5.0 seconds = 5136.800 FPS
25684 frames in 5.0 seconds = 5136.800 FPS
25683 frames in 5.0 seconds = 5136.600 FPS
25682 frames in 5.0 seconds = 5136.400 FPS
> fgl_glxgears
4398 frames in 5.0 seconds = 879.600 FPS
4697 frames in 5.0 seconds = 939.400 FPS
4691 frames in 5.0 seconds = 938.200 FPS
4704 frames in 5.0 seconds = 940.800 FPS
4692 frames in 5.0 seconds = 938.400 FPS
4697 frames in 5.0 seconds = 939.400 FPS
4695 frames in 5.0 seconds = 939.000 FPS
4691 frames in 5.0 seconds = 938.200 FPS
4707 frames in 5.0 seconds = 941.400 FPS
4697 frames in 5.0 seconds = 939.400 FPS
4702 frames in 5.0 seconds = 940.400 FPS
thanks, best regards