~$ glxinfo | grep render
direct rendering: Yes
OpenGL renderer string: GeForce GTX 660/PCIe/SSE2
    GL_ARB_compute_variable_group_size, GL_ARB_conditional_render_inverted, 
    GL_KTX_buffer_region, GL_NVX_conditional_render, GL_NVX_gpu_memory_info, 
    GL_NV_compute_program5, GL_NV_conditional_render, 
    GL_NV_path_rendering, GL_NV_pixel_data_range, GL_NV_point_sprite, 
    GL_ARB_compute_variable_group_size, GL_ARB_conditional_render_inverted, 
    GL_KTX_buffer_region, GL_NVX_conditional_render, GL_NVX_gpu_memory_info, 
    GL_NV_compute_program5, GL_NV_conditional_render, 
    GL_NV_path_rendering, GL_NV_pixel_data_range, GL_NV_point_sprite, 
    GL_EXT_render_snorm, GL_EXT_robustness, GL_EXT_sRGB, 
    GL_NV_conditional_render, GL_NV_copy_buffer, GL_NV_copy_image, 
    GL_NV_path_rendering, GL_NV_pixel_buffer_object, GL_NV_polygon_mode, 
    GL_OES_element_index_uint, GL_OES_fbo_render_mipmap,