Тормоза (~1 fps) в Google Earth 5.0

А другие 3D-приложения и игры работают нормально?

игр у меня нет... но заставки с использванием opengl работаю нормально :-)

Попробуй в гуглоземле вырубить атмосферные эффекты и океан.

отключил - тоже самое :-( на fglrx все работает отлично... но не хочу на него перелазить

А почему бы не выложить сначала логи иксов, glxinfo, или попробовать ati?

>Или в radeonhd 1.2.5 так плохо реализовано ускорение 3D?

В radeonhd нет вообще 3D ускорения, никакого. Так 3D ускорение это mesa + dri + drm + libdrm.

Вывод LIBGL_DEBUG="verbose" glxinfo сюда и вывод /var/log/Xorg.0.log

max@linux-0j6k:~> LIBGL_DEBUG="verbose" glxinfo
name of display: :0.0                          
libGL: XF86DRIGetClientDriverName: 4.3.0 r300 (screen 0)
libGL: OpenDriver: trying /usr/lib64/dri/updates/r300_dri.so
libGL error: dlopen /usr/lib64/dri/updates/r300_dri.so failed (/usr/lib64/dri/updates/r300_dri.so: cannot open shared object file: No such file or directory)   
libGL: OpenDriver: trying /usr/lib64/dri/r300_dri.so                            
drmOpenDevice: node name is /dev/dri/card0                                      
drmOpenDevice: open result is 4, (OK)                                           
drmOpenByBusid: Searching for BusID pci:0000:01:05.0                            
drmOpenDevice: node name is /dev/dri/card0                                      
drmOpenDevice: open result is 4, (OK)                                           
drmOpenByBusid: drmOpenMinor returns 4                                          
drmOpenByBusid: drmGetBusid reports pci:0000:01:05.0                            
libGL error:                                                                    
Can't open configuration file /home/max/.drirc: No such file or directory.      
display: :0  screen: 0                                                          
direct rendering: Yes                                                           
server glx vendor string: SGI                                                   
server glx version string: 1.2                                                  
server glx extensions:                                                          
    GLX_ARB_multisample, GLX_EXT_import_context, GLX_EXT_texture_from_pixmap,   
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_copy_sub_buffer,       
    GLX_OML_swap_method, GLX_SGI_swap_control, GLX_SGIS_multisample,            
    GLX_SGIX_fbconfig, GLX_SGIX_visual_select_group                             
client glx vendor string: SGI                                                   
client glx version string: 1.4                                                  
client glx extensions:                                                          
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,      
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_allocate_memory,       
    GLX_MESA_copy_sub_buffer, GLX_MESA_swap_control,                            
    GLX_MESA_swap_frame_usage, GLX_OML_swap_method, GLX_OML_sync_control,       
    GLX_SGI_make_current_read, GLX_SGI_swap_control, GLX_SGI_video_sync,        
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,                  
    GLX_SGIX_visual_select_group, GLX_EXT_texture_from_pixmap                   
GLX extensions:                                                                 
    GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_import_context,      
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_MESA_swap_control,          
    GLX_MESA_swap_frame_usage, GLX_OML_swap_method, GLX_SGI_swap_control,       
    GLX_SGI_video_sync, GLX_SGIS_multisample, GLX_SGIX_fbconfig,                
    GLX_SGIX_visual_select_group                                                
OpenGL vendor string: DRI R300 Project                                          
OpenGL renderer string: Mesa DRI R300 20060815 NO-TCL                           
OpenGL version string: 1.3 Mesa 7.2                                             
OpenGL extensions:                                                              
    GL_ARB_depth_texture, GL_ARB_fragment_program, GL_ARB_imaging,              
    GL_ARB_multisample, GL_ARB_multitexture, GL_ARB_point_parameters,           
    GL_ARB_shadow, GL_ARB_shadow_ambient, GL_ARB_texture_border_clamp,          
    GL_ARB_texture_compression, GL_ARB_texture_cube_map,                        
    GL_ARB_texture_env_add, GL_ARB_texture_env_combine,                         
    GL_ARB_texture_env_crossbar, GL_ARB_texture_env_dot3,                       
    GL_MESAX_texture_float, GL_ARB_texture_mirrored_repeat,                     
    GL_ARB_texture_rectangle, GL_ARB_transpose_matrix,                          
    GL_ARB_vertex_buffer_object, GL_ARB_vertex_program, GL_ARB_window_pos,      
    GL_EXT_abgr, GL_EXT_bgra, GL_EXT_blend_color,
    GL_EXT_blend_equation_separate, GL_EXT_blend_func_separate,
    GL_EXT_blend_logic_op, GL_EXT_blend_minmax, GL_EXT_blend_subtract,
    GL_EXT_clip_volume_hint, GL_EXT_compiled_vertex_array, GL_EXT_convolution,
    GL_EXT_copy_texture, GL_EXT_draw_range_elements,
    GL_EXT_gpu_program_parameters, GL_EXT_histogram, GL_EXT_multi_draw_arrays,
    GL_EXT_packed_pixels, GL_EXT_point_parameters, GL_EXT_polygon_offset,
    GL_EXT_rescale_normal, GL_EXT_secondary_color,
    GL_EXT_separate_specular_color, GL_EXT_shadow_funcs,
    GL_EXT_stencil_two_side, GL_EXT_stencil_wrap, GL_EXT_subtexture,
    GL_EXT_texture, GL_EXT_texture3D, GL_EXT_texture_edge_clamp,
    GL_EXT_texture_env_add, GL_EXT_texture_env_combine,
    GL_EXT_texture_env_dot3, GL_EXT_texture_filter_anisotropic,
    GL_EXT_texture_lod_bias, GL_EXT_texture_mirror_clamp,
    GL_EXT_texture_object, GL_EXT_texture_rectangle, GL_EXT_vertex_array,
    GL_APPLE_packed_pixels, GL_ATI_blend_equation_separate,
    GL_ATI_texture_env_combine3, GL_ATI_texture_mirror_once,
    GL_IBM_rasterpos_clip, GL_IBM_texture_mirrored_repeat,
    GL_INGR_blend_func_separate, GL_MESA_pack_invert, GL_MESA_ycbcr_texture,
    GL_MESA_window_pos, GL_NV_blend_square, GL_NV_light_max_exponent,
    GL_NV_texture_rectangle, GL_NV_texgen_reflection, GL_NV_vertex_program,
    GL_OES_read_format, GL_SGI_color_matrix, GL_SGI_color_table,
    GL_SGIS_generate_mipmap, GL_SGIS_texture_border_clamp,
    GL_SGIS_texture_edge_clamp, GL_SGIS_texture_lod, GL_SGIX_depth_texture,
    GL_SGIX_shadow_ambient, GL_SUN_multi_draw_arrays
glu version: 1.3
glu extensions:
    GLU_EXT_nurbs_tessellator, GLU_EXT_object_space_tess

libdxt_txcn не ставил?
http://homepage.hispeed.ch/rscheidegger/dri_experimental/s3tc_index.html

Только сейчас вроде поломано, и больше не работает...

нет не ставил... просто поствил систему с нуля и все.