Warning sign: refresh/rasterbeam issues?

1
Hi,
I have a script in which I'm trying to present a couple of moving
circles. At the beginning of every trial I see a giant caution sign
that flashes. This appears even if I set a break point prior to my
trial loops, and it seems to be a function of the initial screen
loading. The code I'm using to do this is: [a, rect] =
Screen('OpenWindow', screenNumber, 255,[], 32, doublebuffer+1), where
screenNumber =0, and doublebuffer = 1.

This may to be due to some sort of function of the discrepancy between
the monitor refresh interval from beamposition (whose values can range
from ~9 to ~13 on any given trial), and the monitor refresh interval
from VBLsync and the operating system, both of which are ~16.677.

An example of the output I get when I run my script with this problem
(for 5 trials) is 5 repetitions of this, with slightly differing
beamposition values each time:
PTB-INFO: Using GLEW version 1.3.5 for automatic detection of OpenGL
extensions...
PTB-INFO: This is the OpenGL-Psychtoolbox version 3.0.8. Type
'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Psychtoolbox is licensed to you under terms of the GNU
General Public License (GPL). See file 'License.txt' in the
PTB-INFO: Psychtoolbox root folder for a copy of the GPL license.

OpenGL-Extensions are: GL_ARB_multitexture GL_EXT_texture_env_add
GL_EXT_compiled_vertex_array GL_S3_s3tc GL_ARB_depth_texture
GL_ARB_fragment_program GL_ARB_fragment_program_shadow
GL_ARB_fragment_shader GL_ARB_multisample GL_ARB_occlusion_query
GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_shader_objects
GL_ARB_shading_language_100 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_transpose_matrix GL_ARB_vertex_blend
GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader
GL_ARB_window_pos GL_ARB_draw_buffers GL_ATI_draw_buffers
GL_ATI_element_array GL_ATI_envmap_bumpmap GL_ATI_fragment_shader
GL_ATI_map_object_buffer GL_ATI_separate_stencil
GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3
GL_ATI_texture_float GL_ATI_texture_mirror_once
GL_ATI_vertex_array_object GL_ATI_vertex_attrib_array_object
GL_ATI_vertex_streams GL_ATIX_texture_env_combine3
GL_ATIX_texture_env_route GL_ATIX_vertex_shader_output_point_size
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_clip_volume_hint
GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object
GL_EXT_multi_draw_arrays GL_EXT_packed_pixels GL_EXT_point_parameters
GL_EXT_rescale_normal GL_EXT_secondary_color
GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap
GL_EXT_texgen_reflection 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_bias GL_EXT_texture_mirror_clamp
GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_vertex_array
GL_EXT_vertex_shader GL_HP_occlusion_test GL_NV_blend_square
GL_NV_occlusion_query GL_NV_texgen_reflection GL_SGI_color_matrix
GL_SGIS_generate_mipmap GL_SGIS_multitexture
GL_SGIS_texture_border_clamp GL_SGIS_texture_edge_clamp
GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint
WGL_EXT_extensions_string WGL_EXT_swap_control

PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Mobility
Radeon X1400 x86/SSE2 :: 2.0.5529 WinXP Release
PTB-Info: VBL startline = 1050 , VBL Endline = 2088805435
PTB-Info: Measured monitor refresh interval from beamposition =
9.907484 ms [100.933797 Hz].
PTB-Info: Will use beamposition query for accurate Flip time stamping.
PTB-Info: Measured monitor refresh interval from VBLsync = 16.738390
ms [59.742903 Hz]. (50 valid samples taken, stddev=0.031696 ms.)
PTB-Info: Reported monitor refresh interval from operating system =
16.666667 ms [60.000000 Hz].
PTB-Info: Small deviations between reported values are normal and no
reason to worry.
PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for
efficient high-performance texture mapping...

WARNING: Mismatch between measured monitor refresh intervals! This
indicates problems with rasterbeam position queries.


----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----

One or more internal checks (see Warnings above) indicate that
queries of rasterbeam position are not properly working for your setup.

Psychtoolbox will work around this by using a different timing algorithm,
but it will cause Screen('Flip') to report less accurate/robust timestamps
for stimulus timing.
Read 'help BeampositionQueries' for more info and troubleshooting tips.


The current version of Psychtoolbox that I'm using is:
3.0.8 - Flavor: stable - Corresponds to SVN Revision 640
For more info visit:
http://svn.berlios.de/wsvn/osxptb/?rev=640&sc=0.

I have also tried the beta version with SVN Revisions up to ( I think
it was) 670 (the latest as of 2 days ago) with the same error. Using
these same versions of Psychtoolbox on a colleague's computer my
script runs fine.

My system specs are: Dell Inspiron I6400 Genuine Intel (R) CPU T2500 @
2.00GHz 2.00 GB of RAM, Windows XP Version 2002. My refresh rate is
set to 60Hz, and my monitor is set to 1.(Multiple Monitors) on ATI
Mobility Radeon X1400 with a resolution of 1680x1050.

I was wondering how to eliminate this warning sign, and also if this
is indicative of deeper issues with respect to timing that I should be
concerned about.

Thank you very much for your help.

Sarah Donohue
Duke University
2
The returned beamposition values (VBL Endline) are completely bogus and strongly
indicate a driver bug in the ATI display driver. Either its a bug wrt. dual-display
configurations or a general bug.

Read "help Beampositionqueries" first.

Update to the latest available graphics driver from ATI for your Laptop. One of the big
problems of Laptops under Windows is that many vendors are pretty bad at providing
timely driver updates, something that Apple does much better.

Try the following, restarting Matlab after each change in display settings:

What happens in single-display mode? If you switch assignment of primary and secondary
display? If you only output to the external display? At lower display resolutions? If you set
resolution of the internal and external screen to identical values?

How does PerceptualVBLSyncTest(0) behave? Does it draw yellow horizontal lines, and
where are they located? What are typical values for the VBL Endline when PTB start up?

When PTB detects such trouble it falls back to a simpler timestamping code, so it doesn't
introduce artifacts, but the timestamps are less robust and accurate (but still as good as
the ones in old PTB 2 or in other toolkits). If none of the above gives an improvements, i'll
tell you how to disable the light-show at least and you'll have to live with slightly less
accurate and robust timestamps.

-mario

--- In psychtoolbox@yahoogroups.com, "donohuesarah" <donohuesarah@...> wrote:
>
> Hi,
> I have a script in which I'm trying to present a couple of moving
> circles. At the beginning of every trial I see a giant caution sign
> that flashes. This appears even if I set a break point prior to my
> trial loops, and it seems to be a function of the initial screen
> loading. The code I'm using to do this is: [a, rect] =
> Screen('OpenWindow', screenNumber, 255,[], 32, doublebuffer+1), where
> screenNumber =0, and doublebuffer = 1.
>
> This may to be due to some sort of function of the discrepancy between
> the monitor refresh interval from beamposition (whose values can range
> from ~9 to ~13 on any given trial), and the monitor refresh interval
> from VBLsync and the operating system, both of which are ~16.677.
>
> An example of the output I get when I run my script with this problem
> (for 5 trials) is 5 repetitions of this, with slightly differing
> beamposition values each time:
> PTB-INFO: Using GLEW version 1.3.5 for automatic detection of OpenGL
> extensions...
> PTB-INFO: This is the OpenGL-Psychtoolbox version 3.0.8. Type
> 'PsychtoolboxVersion' for more detailed version information.
> PTB-INFO: Psychtoolbox is licensed to you under terms of the GNU
> General Public License (GPL). See file 'License.txt' in the
> PTB-INFO: Psychtoolbox root folder for a copy of the GPL license.
>
> OpenGL-Extensions are: GL_ARB_multitexture GL_EXT_texture_env_add
> GL_EXT_compiled_vertex_array GL_S3_s3tc GL_ARB_depth_texture
> GL_ARB_fragment_program GL_ARB_fragment_program_shadow
> GL_ARB_fragment_shader GL_ARB_multisample GL_ARB_occlusion_query
> GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_shader_objects
> GL_ARB_shading_language_100 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_transpose_matrix GL_ARB_vertex_blend
> GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader
> GL_ARB_window_pos GL_ARB_draw_buffers GL_ATI_draw_buffers
> GL_ATI_element_array GL_ATI_envmap_bumpmap GL_ATI_fragment_shader
> GL_ATI_map_object_buffer GL_ATI_separate_stencil
> GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3
> GL_ATI_texture_float GL_ATI_texture_mirror_once
> GL_ATI_vertex_array_object GL_ATI_vertex_attrib_array_object
> GL_ATI_vertex_streams GL_ATIX_texture_env_combine3
> GL_ATIX_texture_env_route GL_ATIX_vertex_shader_output_point_size
> 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_clip_volume_hint
> GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object
> GL_EXT_multi_draw_arrays GL_EXT_packed_pixels GL_EXT_point_parameters
> GL_EXT_rescale_normal GL_EXT_secondary_color
> GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap
> GL_EXT_texgen_reflection 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_bias GL_EXT_texture_mirror_clamp
> GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_vertex_array
> GL_EXT_vertex_shader GL_HP_occlusion_test GL_NV_blend_square
> GL_NV_occlusion_query GL_NV_texgen_reflection GL_SGI_color_matrix
> GL_SGIS_generate_mipmap GL_SGIS_multitexture
> GL_SGIS_texture_border_clamp GL_SGIS_texture_edge_clamp
> GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint
> WGL_EXT_extensions_string WGL_EXT_swap_control
>
> PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Mobility
> Radeon X1400 x86/SSE2 :: 2.0.5529 WinXP Release
> PTB-Info: VBL startline = 1050 , VBL Endline = 2088805435
> PTB-Info: Measured monitor refresh interval from beamposition =
> 9.907484 ms [100.933797 Hz].
> PTB-Info: Will use beamposition query for accurate Flip time stamping.
> PTB-Info: Measured monitor refresh interval from VBLsync = 16.738390
> ms [59.742903 Hz]. (50 valid samples taken, stddev=0.031696 ms.)
> PTB-Info: Reported monitor refresh interval from operating system =
> 16.666667 ms [60.000000 Hz].
> PTB-Info: Small deviations between reported values are normal and no
> reason to worry.
> PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for
> efficient high-performance texture mapping...
>
> WARNING: Mismatch between measured monitor refresh intervals! This
> indicates problems with rasterbeam position queries.
>
>
> ----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----
>
> One or more internal checks (see Warnings above) indicate that
> queries of rasterbeam position are not properly working for your setup.
>
> Psychtoolbox will work around this by using a different timing algorithm,
> but it will cause Screen('Flip') to report less accurate/robust timestamps
> for stimulus timing.
> Read 'help BeampositionQueries' for more info and troubleshooting tips.
>
>
> The current version of Psychtoolbox that I'm using is:
> 3.0.8 - Flavor: stable - Corresponds to SVN Revision 640
> For more info visit:
> http://svn.berlios.de/wsvn/osxptb/?rev=640&sc=0.
>
> I have also tried the beta version with SVN Revisions up to ( I think
> it was) 670 (the latest as of 2 days ago) with the same error. Using
> these same versions of Psychtoolbox on a colleague's computer my
> script runs fine.
>
> My system specs are: Dell Inspiron I6400 Genuine Intel (R) CPU T2500 @
> 2.00GHz 2.00 GB of RAM, Windows XP Version 2002. My refresh rate is
> set to 60Hz, and my monitor is set to 1.(Multiple Monitors) on ATI
> Mobility Radeon X1400 with a resolution of 1680x1050.
>
> I was wondering how to eliminate this warning sign, and also if this
> is indicative of deeper issues with respect to timing that I should be
> concerned about.
>
> Thank you very much for your help.
>
> Sarah Donohue
> Duke University
>
3
Hi Mario,
Thanks for the info! I've tried all of your suggestions including
updating the driver, and I still get the flashing warning sign,
regardless of what I do. When I ran the PerceptualVBLSyncTest(0) I get
yellow lines. One goes across the screen just above the center, and
then the grey square is surround by a black border that has yellow
lines that are located at the top and center that appear to be
occluded by the grey square. The square also isn't uniform, and there
appears to be a triangle that is either a different color or flashing
at a different frequency in the top right corner. The VBL Endline
values seem to always be: 2088805435.
Do you have any other suggestions, or am I at the point where I should
just turn off the warning sign (and how do I do that?), and how off
will this make the time stamps?
Thanks for your help.
Sarah Donohue

--- In psychtoolbox@yahoogroups.com, "Mario Kleiner"
<mario.kleiner@...> wrote:
>
> The returned beamposition values (VBL Endline) are completely bogus
and strongly
> indicate a driver bug in the ATI display driver. Either its a bug
wrt. dual-display
> configurations or a general bug.
>
> Read "help Beampositionqueries" first.
>
> Update to the latest available graphics driver from ATI for your
Laptop. One of the big
> problems of Laptops under Windows is that many vendors are pretty
bad at providing
> timely driver updates, something that Apple does much better.
>
> Try the following, restarting Matlab after each change in display
settings:
>
> What happens in single-display mode? If you switch assignment of
primary and secondary
> display? If you only output to the external display? At lower
display resolutions? If you set
> resolution of the internal and external screen to identical values?
>
> How does PerceptualVBLSyncTest(0) behave? Does it draw yellow
horizontal lines, and
> where are they located? What are typical values for the VBL Endline
when PTB start up?
>
> When PTB detects such trouble it falls back to a simpler
timestamping code, so it doesn't
> introduce artifacts, but the timestamps are less robust and accurate
(but still as good as
> the ones in old PTB 2 or in other toolkits). If none of the above
gives an improvements, i'll
> tell you how to disable the light-show at least and you'll have to
live with slightly less
> accurate and robust timestamps.
>
> -mario
>
> --- In psychtoolbox@yahoogroups.com, "donohuesarah" <donohuesarah@>
wrote:
> >
> > Hi,
> > I have a script in which I'm trying to present a couple of moving
> > circles. At the beginning of every trial I see a giant caution sign
> > that flashes. This appears even if I set a break point prior to my
> > trial loops, and it seems to be a function of the initial screen
> > loading. The code I'm using to do this is: [a, rect] =
> > Screen('OpenWindow', screenNumber, 255,[], 32, doublebuffer+1), where
> > screenNumber =0, and doublebuffer = 1.
> >
> > This may to be due to some sort of function of the discrepancy between
> > the monitor refresh interval from beamposition (whose values can range
> > from ~9 to ~13 on any given trial), and the monitor refresh interval
> > from VBLsync and the operating system, both of which are ~16.677.
> >
> > An example of the output I get when I run my script with this problem
> > (for 5 trials) is 5 repetitions of this, with slightly differing
> > beamposition values each time:
> > PTB-INFO: Using GLEW version 1.3.5 for automatic detection of OpenGL
> > extensions...
> > PTB-INFO: This is the OpenGL-Psychtoolbox version 3.0.8. Type
> > 'PsychtoolboxVersion' for more detailed version information.
> > PTB-INFO: Psychtoolbox is licensed to you under terms of the GNU
> > General Public License (GPL). See file 'License.txt' in the
> > PTB-INFO: Psychtoolbox root folder for a copy of the GPL license.
> >
> > OpenGL-Extensions are: GL_ARB_multitexture GL_EXT_texture_env_add
> > GL_EXT_compiled_vertex_array GL_S3_s3tc GL_ARB_depth_texture
> > GL_ARB_fragment_program GL_ARB_fragment_program_shadow
> > GL_ARB_fragment_shader GL_ARB_multisample GL_ARB_occlusion_query
> > GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_shader_objects
> > GL_ARB_shading_language_100 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_transpose_matrix GL_ARB_vertex_blend
> > GL_ARB_vertex_buffer_object GL_ARB_vertex_program GL_ARB_vertex_shader
> > GL_ARB_window_pos GL_ARB_draw_buffers GL_ATI_draw_buffers
> > GL_ATI_element_array GL_ATI_envmap_bumpmap GL_ATI_fragment_shader
> > GL_ATI_map_object_buffer GL_ATI_separate_stencil
> > GL_ATI_texture_compression_3dc GL_ATI_texture_env_combine3
> > GL_ATI_texture_float GL_ATI_texture_mirror_once
> > GL_ATI_vertex_array_object GL_ATI_vertex_attrib_array_object
> > GL_ATI_vertex_streams GL_ATIX_texture_env_combine3
> > GL_ATIX_texture_env_route GL_ATIX_vertex_shader_output_point_size
> > 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_clip_volume_hint
> > GL_EXT_draw_range_elements GL_EXT_fog_coord GL_EXT_framebuffer_object
> > GL_EXT_multi_draw_arrays GL_EXT_packed_pixels GL_EXT_point_parameters
> > GL_EXT_rescale_normal GL_EXT_secondary_color
> > GL_EXT_separate_specular_color GL_EXT_shadow_funcs GL_EXT_stencil_wrap
> > GL_EXT_texgen_reflection 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_bias GL_EXT_texture_mirror_clamp
> > GL_EXT_texture_object GL_EXT_texture_rectangle GL_EXT_vertex_array
> > GL_EXT_vertex_shader GL_HP_occlusion_test GL_NV_blend_square
> > GL_NV_occlusion_query GL_NV_texgen_reflection GL_SGI_color_matrix
> > GL_SGIS_generate_mipmap GL_SGIS_multitexture
> > GL_SGIS_texture_border_clamp GL_SGIS_texture_edge_clamp
> > GL_SGIS_texture_lod GL_SUN_multi_draw_arrays GL_WIN_swap_hint
> > WGL_EXT_extensions_string WGL_EXT_swap_control
> >
> > PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Mobility
> > Radeon X1400 x86/SSE2 :: 2.0.5529 WinXP Release
> > PTB-Info: VBL startline = 1050 , VBL Endline = 2088805435
> > PTB-Info: Measured monitor refresh interval from beamposition =
> > 9.907484 ms [100.933797 Hz].
> > PTB-Info: Will use beamposition query for accurate Flip time stamping.
> > PTB-Info: Measured monitor refresh interval from VBLsync = 16.738390
> > ms [59.742903 Hz]. (50 valid samples taken, stddev=0.031696 ms.)
> > PTB-Info: Reported monitor refresh interval from operating system =
> > 16.666667 ms [60.000000 Hz].
> > PTB-Info: Small deviations between reported values are normal and no
> > reason to worry.
> > PTB-INFO: Using OpenGL GL_TEXTURE_RECTANGLE_EXT extension for
> > efficient high-performance texture mapping...
> >
> > WARNING: Mismatch between measured monitor refresh intervals! This
> > indicates problems with rasterbeam position queries.
> >
> >
> > ----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----
> >
> > One or more internal checks (see Warnings above) indicate that
> > queries of rasterbeam position are not properly working for your
setup.
> >
> > Psychtoolbox will work around this by using a different timing
algorithm,
> > but it will cause Screen('Flip') to report less accurate/robust
timestamps
> > for stimulus timing.
> > Read 'help BeampositionQueries' for more info and troubleshooting
tips.
> >
> >
> > The current version of Psychtoolbox that I'm using is:
> > 3.0.8 - Flavor: stable - Corresponds to SVN Revision 640
> > For more info visit:
> > http://svn.berlios.de/wsvn/osxptb/?rev=640&sc=0.
> >
> > I have also tried the beta version with SVN Revisions up to ( I think
> > it was) 670 (the latest as of 2 days ago) with the same error. Using
> > these same versions of Psychtoolbox on a colleague's computer my
> > script runs fine.
> >
> > My system specs are: Dell Inspiron I6400 Genuine Intel (R) CPU T2500 @
> > 2.00GHz 2.00 GB of RAM, Windows XP Version 2002. My refresh rate is
> > set to 60Hz, and my monitor is set to 1.(Multiple Monitors) on ATI
> > Mobility Radeon X1400 with a resolution of 1680x1050.
> >
> > I was wondering how to eliminate this warning sign, and also if this
> > is indicative of deeper issues with respect to timing that I should be
> > concerned about.
> >
> > Thank you very much for your help.
> >
> > Sarah Donohue
> > Duke University
> >
>