Graphics and CPU Load

BobNutfield · 05-16-2006, 01:34 PM

Hi Everyone,

I have posted before with concerns about CPU temperature, and I seem to have that resolved (I think). I am just curious now about the termperature vs. load.

I have an nVidia graphics card, FX5500, 256MB, heatsink cooled. During normal web activity and the like, my CPU runs between 30-35C. However, if I run glxgears to examine frame rates, or if a particularly intensive openGL screen saver comes on, the CPU load goes to nearly 100% and the temperature of the CPU jumps quickly to 45-50C. My question is: what is the graphics card doing all this time? Obviously, its running the graphics because, well, they're running. The GPU runs at 400MHz. While I realize that this is not the top of the range graphics card, it is certainly a little on the higher end of average. Why does the CPU have to take so much of the burden when heavy duty graphics are running?

Any thoughts would be appreciated.

Bob

Electro · 05-16-2006, 01:43 PM

A game is a better benchmark tool than glxgears. Though to make sure OpenGL is not using software rendering, run glxinfo and check for the word MESA. If you see MESA, than it is using software rendering. Also make sure renderaccel is on if you are using the nvidia driver.

BobNutfield · 05-16-2006, 01:54 PM

Thank you for your reply. I do not own any heavy duty games for Linux (I do have HL2, Doom3, Call of Duty, etc. for Windows). I don't really every boot into Windows ay more unless I have to get a file or something.

However, glxinfo produced this, and I do not see the word MESA, and I assume direct rendering is what I am looking for:

Quote:

[bob@localhost ~]$ glxinfo
name of display: :0.0
display: :0 screen: 0
direct rendering: Yes
server glx vendor string: NVIDIA Corporation
server glx version string: 1.4
server glx extensions:
GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_SGIX_fbconfig,
GLX_SGIX_pbuffer, GLX_SGI_video_sync, GLX_SGI_swap_control,
GLX_ARB_multisample, GLX_NV_float_buffer
client glx vendor string: NVIDIA Corporation
client glx version string: 1.4
client glx extensions:
GLX_ARB_get_proc_address, GLX_ARB_multisample, GLX_EXT_visual_info,
GLX_EXT_visual_rating, GLX_EXT_import_context, GLX_SGI_video_sync,
GLX_NV_swap_group, GLX_NV_video_out, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer,
GLX_SGI_swap_control, GLX_NV_float_buffer, GLX_ARB_fbconfig_float
GLX version: 1.3
GLX extensions:
GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_SGIX_fbconfig,
GLX_SGIX_pbuffer, GLX_SGI_video_sync, GLX_SGI_swap_control,
GLX_ARB_multisample, GLX_NV_float_buffer, GLX_ARB_get_proc_address
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce FX 5500/AGP/SSE2
OpenGL version string: 2.0.2 NVIDIA 87.56
OpenGL extensions:
GL_ARB_depth_texture, GL_ARB_fragment_program,
GL_ARB_fragment_program_shadow, GL_ARB_fragment_shader,
GL_ARB_half_float_pixel, GL_ARB_imaging, GL_ARB_multisample,
GL_ARB_multitexture, GL_ARB_occlusion_query, GL_ARB_pixel_buffer_object,
GL_ARB_point_parameters, GL_ARB_point_sprite, GL_ARB_shadow,
GL_ARB_shader_objects, GL_ARB_shading_language_100,
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_dot3,
GL_ARB_texture_mirrored_repeat, GL_ARB_texture_rectangle,
GL_ARB_transpose_matrix, GL_ARB_vertex_buffer_object,
GL_ARB_vertex_program, GL_ARB_vertex_shader, GL_ARB_window_pos,
GL_S3_s3tc, GL_EXT_texture_env_add, GL_EXT_abgr, GL_EXT_bgra,
GL_EXT_blend_color, GL_EXT_blend_func_separate, GL_EXT_blend_minmax,
GL_EXT_blend_subtract, GL_EXT_compiled_vertex_array, GL_EXT_Cg_shader,
GL_EXT_draw_range_elements, GL_EXT_fog_coord, GL_EXT_framebuffer_object,
GL_EXT_multi_draw_arrays, GL_EXT_packed_depth_stencil,
GL_EXT_packed_pixels, GL_EXT_paletted_texture, GL_EXT_pixel_buffer_object,
GL_EXT_point_parameters, 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_two_side,
GL_EXT_stencil_wrap, GL_EXT_texture3D, GL_EXT_texture_compression_s3tc,
GL_EXT_texture_cube_map, GL_EXT_texture_edge_clamp,
GL_EXT_texture_env_combine, GL_EXT_texture_env_dot3,
GL_EXT_texture_filter_anisotropic, GL_EXT_texture_lod,
GL_EXT_texture_lod_bias, GL_EXT_texture_object, GL_EXT_texture_sRGB,
GL_EXT_timer_query, GL_EXT_vertex_array, GL_HP_occlusion_test,
GL_IBM_rasterpos_clip, GL_IBM_texture_mirrored_repeat,
GL_KTX_buffer_region, GL_NV_blend_square, GL_NV_copy_depth_to_color,
GL_NV_depth_clamp, GL_NV_fence, GL_NV_float_buffer, GL_NV_fog_distance,
GL_NV_fragment_program, GL_NV_fragment_program_option, GL_NV_half_float,
GL_NV_light_max_exponent, GL_NV_multisample_filter_hint,
GL_NV_occlusion_query, GL_NV_packed_depth_stencil, GL_NV_pixel_data_range,
GL_NV_point_sprite, GL_NV_primitive_restart, GL_NV_register_combiners,
GL_NV_register_combiners2, GL_NV_texgen_reflection,
GL_NV_texture_compression_vtc, GL_NV_texture_env_combine4,
GL_NV_texture_expand_normal, GL_NV_texture_rectangle,
GL_NV_texture_shader, GL_NV_texture_shader2, GL_NV_texture_shader3,
GL_NV_vertex_array_range, GL_NV_vertex_array_range2, GL_NV_vertex_program,
GL_NV_vertex_program1_1, GL_NV_vertex_program2,
GL_NV_vertex_program2_option, GL_SGIS_generate_mipmap,
GL_SGIS_texture_lod, GL_SGIX_depth_texture, GL_SGIX_shadow,
GL_SUN_slice_accum
glu version: 1.3
glu extensions:
GLU_EXT_nurbs_tessellator, GLU_EXT_object_space_tess

I would have to research each line to determine what all of that means, but I assume everything is as it should be. I just don't understand why the CPU runs so hot with graphics.

Bob

Simon Bridge · 05-22-2006, 06:19 PM

I'll second an interest in this one.
I have Ubuntu Dapper (beta2 but updated since) with ASUS nv6600 (geforce) using the deb packaged driver. As with you, it goes. Games goes ... however I notice thatCPU emp goes up and the load regularily goes above 30%.

Watchine the top utility - the load hits 100% just opening a window. And it is XOrg that takes most of this. Just moving the terminal running tops around runs Xorg's share of the cpu load up to 40%

glxinfo produces similar output to above.