Binary package hint: xserver-xorg-video-intel
After a fresh startup:
User "A" logs in. glxgears runs at 1214 fps. The gears rotate smoothly, 3D acceleration is visually OK.
User "B" logs in, glxgears says it runs at "only" 286 fps. But visually it looks like it's not 3D accelerated at all. The real refresh rate is about 3 fps.
NB : after a reboot, if user "B" logs in before user "A", "B" gets the full 3D acceleration.
Driver: xserver-xorg-video-intel
Version: 2:2.1.1-0ubuntu9.1
$ lsb_release -rd
Description: Ubuntu 7.10
Release: 7.10
$ glxgears -info
GL_RENDERER = Mesa GLX Indirect
GL_VERSION = 1.4 (2.1 Mesa 7.0.1)
GL_VENDOR = Mesa project: www.mesa3d.org
GL_EXTENSIONS = GL_ARB_depth_texture GL_ARB_draw_buffers GL_ARB_fragment_program GL_ARB_imaging GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_point_parameters GL_ARB_point_sprite 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_ARB_texture_mirrored_repeat GL_ARB_texture_non_power_of_two GL_ARB_texture_rectangle GL_ARB_transpose_matrix 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_copy_texture GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object GL_EXT_multi_draw_arrays GL_EXT_packed_pixels GL_EXT_paletted_texture 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_shared_texture_palette 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_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_draw_buffers GL_ATI_texture_env_combine3 GL_ATI_texture_mirror_once GL_ATIX_texture_env_combine3 GL_IBM_texture_mirrored_repeat GL_INGR_blend_func_separate GL_MESA_pack_invert GL_MESA_ycbcr_texture GL_NV_blend_square GL_NV_fragment_program GL_NV_light_max_exponent GL_NV_point_sprite GL_NV_texgen_reflection GL_NV_texture_rectangle GL_NV_vertex_program GL_NV_vertex_program1_1 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 GL_SGIX_shadow_ambient GL_SUN_multi_draw_arrays
Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug #137745, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can add, or to see if there is a workaround for the bug.
Feel free to continue to report any other bugs you may find.