Hi all -
I am setting up a new machine that will be repeated 3x, and I’m having some sync trouble. We have priority support but I am asking in public in case it benefits anyone (hopefully it all benefits everyone).
My machine runs Ubuntu 20.04 (fully updated as of yesterday Ubuntu 20.04.3 LTS (GNU/Linux 5.11.0-37-generic x86_64)) and has a built-in Intel graphics board for the display that the operator uses, and a Radeon 5100 for the display that drives a CRT at 100 Hz refresh (connected through an HDMI adapter). The system is set up as a 2 screen system (with “ZaphodHeads”), where screen 0 is the monitor connected to the Intel board and screen 1 is the monitor connected to the Radeon 5100 board.
I have installed the current version of Psychtoolbox using the neurodebian package for Matlab. I have installed the matlab-support package and allowed it to rename the C++ libraries. I run Matlab R2021a Update 5 (9.10.0.1739362) 64-bit (glnxa64).
Symptoms: Psychtoolbox runs fine on a 60Hz LCD display connected to the Intel board (screen 0), but I have no VBL sync information on the Radeon-connected CRT. It appears to me that it is using the MESA driver rather than the proprietary driver (as it should). If I force Psychtoolbox to ignore the sync failures, it will draw the stimuli on the CRT just fine but of course there is terrible tearing.
Now, the debugging information. I’ll paste the report when I try to use the Radeon-connected monitor (which fails), the report when I use the Intel board (which succeeds on an LCD but I’d like to use the nice Radeon 5100 for my work), and my xorg.conf information and my custom xrandr setup, and some libGL errors that I don’t think are relevant but might be.
The debugging info is too long to fit into one message so I will post the rest in a reply.
- DEBUGGING INFO: Verbose output when I use the Radeon-connected monitor (screen 1), which fails:
PTB-DEBUG: PsychReadNormalizedGammaTable: Provided RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychReadNormalizedGammaTable: Provided RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: Required RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: LUT size nIn 1024 <= nOut 1024 → Oversample 1 times.
PTB-DEBUG: PsychReadNormalizedGammaTable: Provided RandR HW-LUT size is n=1024.
RandR: 800x600_100 (0x8b1) 67.2MHz
h: width 800 start 848 end 928 total 1056 skew 0
v: height 600 start 603 end 607 total 639
PTB-INFO: This is Psychtoolbox-3 for GNU/Linux X11, under Matlab 64-Bit (Version 3.0.17 - Build date: May 14 2021).
PTB-INFO: OS support status: Linux 5.11.0-37-generic Supported.
PTB-INFO: Type ‘PsychtoolboxVersion’ for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file ‘License.txt’ in the Psychtoolbox root folder for the exact licensing conditions.
PTB-INFO: For information about paid priority support, community membership and commercial services, please type
PTB-INFO: ‘PsychPaidSupportAndServices’.
PTB-DEBUG: Checking PCI device [Intel Corporation 8th Gen Core 8-core Desktop Processor Host Bridge/DRAM Registers [Coffee Lake S]] with class x00060000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Controller (x16)] with class x00060400 …
PTB-DEBUG: Checking PCI device [Intel Corporation UHD Graphics 630 (Desktop 9 Series)] with class x00030000 …
PTB-INFO: Skipping detected Intel GPU for safety reasons. setenv(‘PSYCH_ALLOW_DANGEROUS’, ‘1’) to override.
PTB-DEBUG: Checking PCI device [Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model] with class x00088000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH Thermal Controller] with class x00118000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH USB 3.1 xHCI Host Controller] with class x000c0330 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH Shared SRAM] with class x00050000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH Serial IO I2C Controller #0] with class x000c8000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH HECI Controller] with class x00078000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH SATA AHCI Controller] with class x00010601 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH PCI Express Root Port #17] with class x00060400 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH PCI Express Root Port #9] with class x00060400 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH PCI Express Root Port #11] with class x00060400 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Point-LP LPC Controller] with class x00060100 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH cAVS] with class x00040300 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH SMBus Controller] with class x000c0500 …
PTB-DEBUG: Checking PCI device [Intel Corporation Cannon Lake PCH SPI Controller] with class x000c8000 …
PTB-DEBUG: Checking PCI device [Intel Corporation Ethernet Connection (7) I219-LM] with class x00020000 …
PTB-DEBUG: Checking PCI device [Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon Pro WX 5100]] with class x00030000 …
PTB-DEBUG: Checking PCI device [Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590]] with class x00040300 …
PTB-DEBUG: Checking PCI device [Micron Technology Inc (null)] with class x00010802 …
PTB-DEBUG: Checking PCI device [ASMedia Technology Inc. ASM1083/1085 PCIe to PCI Bridge] with class x00060400 …
PTB-INFO: No low-level controllable GPU on screenId 0. Beamposition timestamping and other special functions disabled.
PTB-INFO: Using old-style override-redirect (=1) setup path for onscreen window creation.
PTB-INFO: GLX Visual info depths is 24 bits
PTB-INFO: Running on Mesa version 21.0.3
PTB-INFO: This combo of X-Server and Mesa is considered safe for use under DRI3/Present.
PTB-INFO: Using GLEW version 2.1.0 for automatic detection of OpenGL extensions…
PTB-WARNING: Your graphics driver doesn’t allow me to control syncing wrt. vertical retrace!
PTB-WARNING: Please update your display graphics driver as soon as possible to fix this.
PTB-WARNING: Until then, you can manually enable syncing to VBL somehow in a manner that is
PTB-WARNING: dependent on the type of gfx-card and driver. Google is your friend…
PTB-INFO: Disabling VRR Variable Refresh Rate mode for this fullscreen window on Mesa graphics driver.
PTB-INFO: INTEL_swap_event support for additional swap completion correctness checks enabled.
PTB-INFO: Fixed point precision integer framebuffer enabled.
PTB-INFO: System Frame buffer provides 8 bits for red channel.
PTB-INFO: System Frame buffer provides 8 bits for green channel.
PTB-INFO: System Frame buffer provides 8 bits for blue channel.
PTB-INFO: System frame buffer provides 8 bits for alpha channel, but effective alpha bits depends on imaging pipeline setup, if any.
PTB-DEBUG: PPM file magic is P6
→ Ok
Created by GIMP version 2.10.22 PNM plug-in
PTB-DEBUG: Recognized splash image of 1000 x 750 pixels, maxlevel 255. Loading…
OpenGL-Vendor / renderer / version are: Mesa/X.org - llvmpipe (LLVM 12.0.0, 256 bits) - 3.1 Mesa 21.0.3
OpenGL-Extensions are: GL_ARB_multisample GL_EXT_abgr GL_EXT_bgra GL_EXT_blend_color GL_EXT_blend_minmax GL_EXT_blend_subtract GL_EXT_copy_texture GL_EXT_subtexture GL_EXT_texture_object GL_EXT_vertex_array GL_EXT_compiled_vertex_array GL_EXT_texture GL_EXT_texture3D GL_IBM_rasterpos_clip GL_ARB_point_parameters GL_EXT_draw_range_elements GL_EXT_packed_pixels GL_EXT_point_parameters GL_EXT_rescale_normal GL_EXT_separate_specular_color GL_EXT_texture_edge_clamp GL_SGIS_generate_mipmap GL_SGIS_texture_border_clamp GL_SGIS_texture_edge_clamp GL_SGIS_texture_lod GL_ARB_framebuffer_sRGB GL_ARB_multitexture GL_EXT_framebuffer_sRGB GL_IBM_multimode_draw_arrays GL_IBM_texture_mirrored_repeat GL_ARB_texture_cube_map GL_ARB_texture_env_add GL_ARB_transpose_matrix GL_EXT_blend_func_separate GL_EXT_fog_coord GL_EXT_multi_draw_arrays GL_EXT_secondary_color GL_EXT_texture_env_add GL_EXT_texture_lod_bias GL_INGR_blend_func_separate GL_NV_blend_square GL_NV_light_max_exponent GL_NV_texgen_reflection GL_NV_texture_env_combine4 GL_S3_s3tc GL_SUN_multi_draw_arrays GL_ARB_texture_border_clamp GL_ARB_texture_compression GL_EXT_framebuffer_object GL_EXT_texture_compression_s3tc GL_EXT_texture_env_combine GL_EXT_texture_env_dot3 GL_MESA_window_pos GL_NV_packed_depth_stencil GL_NV_texture_rectangle GL_ARB_depth_texture GL_ARB_occlusion_query GL_ARB_shadow GL_ARB_texture_env_combine GL_ARB_texture_env_crossbar GL_ARB_texture_env_dot3 GL_ARB_texture_mirrored_repeat GL_ARB_window_pos GL_ATI_fragment_shader GL_EXT_stencil_two_side GL_EXT_texture_cube_map GL_NV_copy_depth_to_color GL_NV_depth_clamp GL_NV_fog_distance GL_NV_half_float GL_APPLE_packed_pixels GL_ARB_draw_buffers GL_ARB_fragment_program GL_ARB_fragment_shader GL_ARB_shader_objects GL_ARB_vertex_program GL_ARB_vertex_shader GL_ATI_draw_buffers GL_ATI_texture_env_combine3 GL_ATI_texture_float GL_EXT_shadow_funcs GL_EXT_stencil_wrap GL_MESA_pack_invert GL_MESA_ycbcr_texture GL_NV_primitive_restart GL_ARB_depth_clamp GL_ARB_fragment_program_shadow GL_ARB_half_float_pixel GL_ARB_occlusion_query2 GL_ARB_point_sprite GL_ARB_shading_language_100 GL_ARB_sync GL_ARB_texture_non_power_of_two GL_ARB_vertex_buffer_object GL_ATI_blend_equation_separate GL_EXT_blend_equation_separate GL_OES_read_format GL_ARB_color_buffer_float GL_ARB_pixel_buffer_object GL_ARB_texture_compression_rgtc GL_ARB_texture_float GL_ARB_texture_rectangle GL_ATI_texture_compression_3dc GL_EXT_packed_float GL_EXT_pixel_buffer_object GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_rgtc GL_EXT_texture_mirror_clamp GL_EXT_texture_rectangle GL_EXT_texture_sRGB GL_EXT_texture_shared_exponent GL_ARB_framebuffer_object GL_EXT_framebuffer_blit GL_EXT_framebuffer_multisample GL_EXT_packed_depth_stencil GL_ARB_vertex_array_object GL_ATI_separate_stencil GL_ATI_texture_mirror_once GL_EXT_draw_buffers2 GL_EXT_draw_instanced GL_EXT_gpu_program_parameters GL_EXT_gpu_shader4 GL_EXT_texture_array GL_EXT_texture_compression_latc GL_EXT_texture_integer GL_EXT_texture_sRGB_decode GL_EXT_timer_query GL_OES_EGL_image GL_EXT_texture_buffer_object GL_AMD_texture_texture4 GL_ARB_copy_buffer GL_ARB_depth_buffer_float GL_ARB_draw_instanced GL_ARB_half_float_vertex GL_ARB_instanced_arrays GL_ARB_map_buffer_range GL_ARB_texture_buffer_object GL_ARB_texture_rg GL_ARB_texture_swizzle GL_ARB_vertex_array_bgra GL_EXT_texture_swizzle GL_EXT_vertex_array_bgra GL_NV_conditional_render GL_AMD_conservative_depth GL_AMD_draw_buffers_blend GL_AMD_seamless_cubemap_per_texture GL_AMD_shader_stencil_export GL_ARB_ES2_compatibility GL_ARB_blend_func_extended GL_ARB_compatibility GL_ARB_debug_output GL_ARB_draw_buffers_blend GL_ARB_draw_elements_base_vertex GL_ARB_explicit_attrib_location GL_ARB_fragment_coord_conventions GL_ARB_provoking_vertex GL_ARB_sample_shading GL_ARB_sampler_objects GL_ARB_seamless_cube_map GL_ARB_shader_stencil_export GL_ARB_shader_texture_lod GL_ARB_texture_buffer_object_rgb32 GL_ARB_texture_cube_map_array GL_ARB_texture_gather GL_ARB_texture_multisample GL_ARB_texture_query_lod GL_ARB_texture_rgb10_a2ui GL_ARB_uniform_buffer_object GL_ARB_vertex_type_2_10_10_10_rev GL_EXT_provoking_vertex GL_EXT_texture_snorm GL_MESA_texture_signed_rgba GL_NV_copy_image GL_NV_texture_barrier GL_ARB_draw_indirect GL_ARB_get_program_binary GL_ARB_robustness GL_ARB_separate_shader_objects GL_ARB_shader_bit_encoding GL_ARB_shader_subroutine GL_ARB_texture_compression_bptc GL_ARB_timer_query GL_ARB_transform_feedback2 GL_ARB_transform_feedback3 GL_ARB_viewport_array GL_EXT_direct_state_access GL_AMD_multi_draw_indirect GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ARB_base_instance GL_ARB_compressed_texture_pixel_storage GL_ARB_conservative_depth GL_ARB_internalformat_query GL_ARB_map_buffer_alignment GL_ARB_shader_atomic_counters GL_ARB_shader_image_load_store GL_ARB_shading_language_420pack GL_ARB_shading_language_packing GL_ARB_texture_storage GL_ARB_transform_feedback_instanced GL_EXT_framebuffer_multisample_blit_scaled GL_EXT_transform_feedback GL_AMD_query_buffer_object GL_AMD_shader_trinary_minmax GL_ARB_ES3_compatibility GL_ARB_arrays_of_arrays GL_ARB_clear_buffer_object GL_ARB_compute_shader GL_ARB_copy_image GL_ARB_explicit_uniform_location GL_ARB_fragment_layer_viewport GL_ARB_framebuffer_no_attachments GL_ARB_invalidate_subdata GL_ARB_multi_draw_indirect GL_ARB_program_interface_query GL_ARB_robust_buffer_access_behavior GL_ARB_shader_image_size GL_ARB_shader_storage_buffer_object GL_ARB_stencil_texturing GL_ARB_texture_buffer_range GL_ARB_texture_query_levels GL_ARB_texture_storage_multisample GL_ARB_texture_view GL_ARB_vertex_attrib_binding GL_KHR_debug GL_KHR_robustness GL_KHR_texture_compression_astc_ldr GL_ARB_buffer_storage GL_ARB_clear_texture GL_ARB_enhanced_layouts GL_ARB_indirect_parameters GL_ARB_internalformat_query2 GL_ARB_multi_bind GL_ARB_query_buffer_object GL_ARB_seamless_cubemap_per_texture GL_ARB_shader_draw_parameters GL_ARB_shader_group_vote GL_ARB_shading_language_include GL_ARB_texture_mirror_clamp_to_edge GL_ARB_texture_stencil8 GL_ARB_vertex_type_10f_11f_11f_rev GL_EXT_shader_integer_mix GL_ARB_clip_control GL_ARB_conditional_render_inverted GL_ARB_cull_distance GL_ARB_derivative_control GL_ARB_direct_state_access GL_ARB_get_texture_sub_image GL_ARB_pipeline_statistics_query GL_ARB_shader_texture_image_samples GL_ARB_texture_barrier GL_ARB_transform_feedback_overflow_query GL_EXT_polygon_offset_clamp GL_KHR_blend_equation_advanced GL_KHR_context_flush_control GL_KHR_robust_buffer_access_behavior GL_ARB_parallel_shader_compile GL_ARB_post_depth_coverage GL_ARB_shader_atomic_counter_ops GL_EXT_texture_sRGB_R8 GL_KHR_no_error GL_KHR_texture_compression_astc_sliced_3d GL_MESA_shader_integer_functions GL_ARB_polygon_offset_clamp GL_KHR_parallel_shader_compile GL_EXT_EGL_image_storage GL_EXT_shader_framebuffer_fetch_non_coherent GL_EXT_texture_shadow_lod GL_EXT_EGL_sync
PTB-DEBUG: Running on Mesa version 21.0.3
PTB-DEBUG: Linux X11 backend with non-NVidia blob drivers - Enabling locked pixeltoken-write + flush workaround for XLib thread-safety.
PTB-DEBUG: Interrogating Low-level renderer capabilities for onscreen window with handle 10:
Indicator variables: FBO’s 1, ATI_texture_float 1, ARB_texture_float 1, Vendor Mesa/X.org, Renderer llvmpipe (LLVM 12.0.0, 256 bits).
Indicator variables: maxcolorattachments = 8, maxrectangletexturesize = 16384, maxnativealuinstructions = 1048576.
GPU supports UYVY - YCrCb texture formats for optimized handling of video content.
GPU supports non-power-of-two textures.
Hardware supports signed normalized textures of 16 bpc integer format.
Basic framebuffer objects with rectangle texture rendertargets supported → RGBA8 rendertargets with blending.
Framebuffer objects support fast blitting between each other.
Framebuffer objects support anti-aliasing via multisampling.
Framebuffer objects support single-pass multisample resolve blits and image rescaling.
Hardware supports floating point textures of 16bpc and 32bpc float format.
Assuming Gallium LLVM-Pipe rasterizer: Renderer supports full 16/32 bit floating point textures, frame buffers, filtering and blending, as well as some 32 bit float shading.
Float color value 0.5 → fixed point reads back as 128 ==> Rounds.
PTB-Info: Running on ‘The X.Org Foundation’ XServer, Vendor release 12011000.
OML_sync_control indicators: glXGetSyncValuesOML=0x7fd880218770 , glXWaitForMscOML=0x7fd880218bd0, glXWaitForSbcOML=0x7fd880218c80, glXSwapBuffersMscOML=0x7fd880218aa0
OML_sync_control indicators: glxewIsSupported() says 1.
OML_sync_control indicators: glXQueryExtensionsString() says 0.
No support for OpenML OML_sync_control extension.
PTB-DEBUG: Interrogation done.
RandR: 800x600_100 (0x8b1) 67.2MHz
h: width 800 start 848 end 928 total 1056 skew 0
v: height 600 start 603 end 607 total 639
RandR: 800x600_100 (0x8b1) 67.2MHz
h: width 800 start 848 end 928 total 1056 skew 0
v: height 600 start 603 end 607 total 639
PTB-DEBUG: glClear splash image top-left reference pixel: 90 0 90
PTB-INFO: Threshold Settings for successfull video refresh calibration are: maxStdDev = 0.200000 msecs, maxDeviation = 10.000000 %, minSamples = 50, maxDuration = 5.000000 secs.
PTB-WARNING: Couldn’t even collect one single valid flip interval sample! Sanity range checks failed!
PTB-WARNING: Could be a system bug, or a temporary timing problem. Retrying the procedure might help if
PTB-WARNING: the latter is the culprit.
PTB-WARNING: Couldn’t collect valid flip interval samples! Fatal VBL sync failure!
PTB-WARNING: Either synchronization of doublebuffer swapping to the vertical retrace signal of your display is broken,
PTB-WARNING: or the mechanism for detection of swap completion is broken. In any case, this is an operating system or gfx-driver bug!
PTB-DEBUG: Output of all acquired samples of calibration run follows:
PTB-DEBUG: Sample 0: 0.000000
PTB-DEBUG: Sample 1: 0.002723
PTB-DEBUG: Sample 2: 0.002206
PTB-DEBUG: Sample 3: 0.002417
PTB-DEBUG: Sample 4: 0.002140
PTB-DEBUG: Sample 5: 0.001980
PTB-DEBUG: Sample 6: 0.002268
PTB-DEBUG: Sample 7: 0.002051
PTB-DEBUG: Sample 8: 0.001939
PTB-DEBUG: Sample 9: 0.001906
PTB-DEBUG: Sample 10: 0.001934
PTB-DEBUG: End of calibration data for this run…
WARNING: VBL Calibration run No. 1 failed. Retrying…
PTB-WARNING: Couldn’t even collect one single valid flip interval sample! Sanity range checks failed!
PTB-WARNING: Could be a system bug, or a temporary timing problem. Retrying the procedure might help if
PTB-WARNING: the latter is the culprit.
PTB-WARNING: Couldn’t collect valid flip interval samples! Fatal VBL sync failure!
PTB-WARNING: Either synchronization of doublebuffer swapping to the vertical retrace signal of your display is broken,
PTB-WARNING: or the mechanism for detection of swap completion is broken. In any case, this is an operating system or gfx-driver bug!
PTB-DEBUG: Output of all acquired samples of calibration run follows:
PTB-DEBUG: Sample 0: 0.000000
PTB-DEBUG: Sample 1: 0.002079
PTB-DEBUG: Sample 2: 0.002049
PTB-DEBUG: Sample 3: 0.002008
PTB-DEBUG: Sample 4: 0.001908
PTB-DEBUG: Sample 5: 0.002076
PTB-DEBUG: Sample 6: 0.001980
PTB-DEBUG: Sample 7: 0.002126
PTB-DEBUG: Sample 8: 0.002033
PTB-DEBUG: Sample 9: 0.002088
PTB-DEBUG: Sample 10: 0.001867
PTB-DEBUG: End of calibration data for this run…
WARNING: VBL Calibration run No. 2 failed. Retrying…
WARNING: Will enable VBL busywait-workaround before trying final VBL Calibration run No. 3.
WARNING: This will hopefully work-around graphics driver bugs of the GPU sync-to-retrace mechanism. Cross your fingers!
PTB-DEBUG: Output of all acquired samples of calibration run follows:
PTB-DEBUG: Sample 0: 0.000000
PTB-DEBUG: Sample 1: 0.001977
PTB-DEBUG: Sample 2: 0.002079
PTB-DEBUG: Sample 3: 0.004208
PTB-DEBUG: Sample 4: 0.004416
PTB-DEBUG: Sample 5: 0.004538
PTB-DEBUG: Sample 6: 0.004428
PTB-DEBUG: Sample 7: 0.004885
PTB-DEBUG: Sample 8: 0.004660
PTB-DEBUG: Sample 9: 0.004626
PTB-DEBUG: Sample 10: 0.004414
PTB-DEBUG: Sample 11: 0.004381
PTB-DEBUG: Sample 12: 0.004527
PTB-DEBUG: Sample 13: 0.004480
PTB-DEBUG: Sample 14: 0.004720
PTB-DEBUG: Sample 15: 0.004465
PTB-DEBUG: Sample 16: 0.004280
PTB-DEBUG: Sample 17: 0.004052
PTB-DEBUG: Sample 18: 0.004184
PTB-DEBUG: Sample 19: 0.004044
PTB-DEBUG: Sample 20: 0.004164
PTB-DEBUG: Sample 21: 0.004117
PTB-DEBUG: Sample 22: 0.004213
PTB-DEBUG: Sample 23: 0.004098
PTB-DEBUG: Sample 24: 0.003958
PTB-DEBUG: Sample 25: 0.004064
PTB-DEBUG: Sample 26: 0.004167
PTB-DEBUG: Sample 27: 0.004275
PTB-DEBUG: Sample 28: 0.004211
PTB-DEBUG: Sample 29: 0.004170
PTB-DEBUG: Sample 30: 0.004290
PTB-DEBUG: Sample 31: 0.004251
PTB-DEBUG: Sample 32: 0.003958
PTB-DEBUG: Sample 33: 0.003941
(I now truncate this list)
PTB-INFO: OpenGL-Renderer is Mesa/X.org :: llvmpipe (LLVM 12.0.0, 256 bits) :: 3.1 Mesa 21.0.3
PTB-INFO: VBL startline = 600 , VBL Endline = -1
PTB-INFO: Beamposition queries unsupported or defective on this system. Using basic timestamping as fallback.
PTB-INFO: Timestamps returned by Screen(‘Flip’) will be therefore less robust and accurate.
PTB-INFO: Measured monitor refresh interval from VBLsync = 9.991169 ms [100.088388 Hz]. (1 valid samples taken, stddev=10000000.000000 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 10.034116 ms [99.660004 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
WARNING: Couldn’t compute a reliable estimate of monitor refresh interval! Trouble with VBL syncing?!?
----- ! PTB - ERROR: SYNCHRONIZATION FAILURE ! -----
One or more internal checks (see Warnings above) indicate that synchronization
of Psychtoolbox to the vertical retrace (VBL) is not working on your setup.
This will seriously impair proper stimulus presentation and stimulus presentation timing!
Please read ‘help SyncTrouble’ for information about how to solve or work-around the problem.
You can force Psychtoolbox to continue, despite the severe problems, by adding the command
Screen(‘Preference’, ‘SkipSyncTests’, 1); at the top of your script, if you really know what you are doing.
PTB-DEBUG:PsychOSCloseWindow: Closing with a final swapbuffers count of 0.
PTB-DEBUG: Releasing pointer barriers for window 10.
Error using Screen
See error message printed above.
PTB-DEBUG: PsychReadNormalizedGammaTable: Provided RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: Required RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: LUT size nIn 1024 <= nOut 1024 → Oversample 1 times.
PTB-DEBUG: PsychReadNormalizedGammaTable: Provided RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: Required RandR HW-LUT size is n=1024.
PTB-DEBUG: PsychLoadNormalizedGammaTable: LUT size nIn 1024 <= nOut 1024 → Oversample 1 times.