# Errors with VBLSyncTest and Screen('Flip') **URL:** \ **Category:** Uncategorized\ **Created:** [May 19, 2008, 7:17pm UTC](https://psychtoolbox.discourse.group/t/errors-with-vblsynctest-and-screen-39-flip-39/1975 "2008-05-19T19:17:48Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Post date:** [May 19, 2008, 7:17pm UTC](https://psychtoolbox.discourse.group/t/errors-with-vblsynctest-and-screen-39-flip-39/1975/1 "2008-05-19T19:17:48Z")
I am on a Toshiba Satellite P-200 with ATI Mobility Radeon 2600 4Gb Ram Vista Ultimate. I was trying to do the very first tutorial and I cannot even open the window without having errors. I have tried everything I could find. I fixed the beamposition error by disabling my antivirus but still cannot get anything on VBLsync or get anything with Screen('Flip'). Thanks David > \>\> VBLSyncTest() screenwidth = 1680 screenheight = 1050 PTB-INFO: This is the OpenGL-Psychtoolbox for Microsoft Windows, version 3.0.8. (Build date: Apr 16 2008) PTB-INFO: 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\_depth\_texture GL\_ARB\_draw\_buffers GL\_ARB\_fragment\_program GL\_ARB\_fragment\_shader GL\_ARB\_multisample GL\_ARB\_multitexture GL\_ARB\_occlusion\_query GL\_ARB\_point\_parameters 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\_float GL\_ARB\_texture\_mirrored\_repeat GL\_ARB\_texture\_non\_power\_of\_two 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\_ATI\_draw\_buffers GL\_ATI\_envmap\_bumpmap GL\_ATI\_fragment\_shader GL\_ATI\_meminfo GL\_ATI\_separate\_stencil GL\_ATI\_texture\_compression\_3dc GL\_ATI\_texture\_env\_combine3 GL\_ATI\_texture\_float 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\_copy\_texture 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\_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\_subtexture 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\_add 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\_KTX\_buffer\_region GL\_NV\_blend\_square GL\_NV\_texgen\_reflection GL\_SGIS\_generate\_mipmap GL\_SGIS\_texture\_edge\_clamp GL\_SGIS\_texture\_lod GL\_WIN\_swap\_hint WGL\_EXT\_swap\_control PTB-ERROR: Mismatch between requested display swap interval 1 and actual swap interval 0! Synchronization of Screen('Flip') to display refresh will likely malfunction! PTB-ERROR: This is either a bug in your graphics driver or system setup, or some misconfiguration in the display setting control panel of your system. See 'help SyncTrouble' for more info. PTB-WARNING: Couldn't even collect one single valid flip interval sample! Sanity range checks failed! PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL sync failure! PTB-WARNING: Couldn't even collect one single valid flip interval sample! Sanity range checks failed! PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL sync failure! PTB-WARNING: Couldn't even collect one single valid flip interval sample! Sanity range checks failed! PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL sync failure! PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Mobility Radeon HD 2600 :: 2.0.6479 Release PTB-Info: VBL startline = 1050 , VBL Endline = 1095 PTB-Info: Measured monitor refresh interval from beamposition = 17.009855 ms [58.789449 Hz]. PTB-Info: Will use beamposition query for accurate Flip time stamping. PTB-Info: Measured monitor refresh interval from VBLsync = 0.000000 ms [1.#INF00 Hz]. (0 valid samples taken, stddev=1000000000.000000 ms.) PTB-Info: Reported monitor refresh interval from operating system = 16.949153 ms [59.000000 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?!? WARNING: Mismatch between measured monitor refresh interval and interval reported by operating system. This indicates massive problems with VBL sync. WARNING: Measured monitor refresh interval indicates a display refresh of less than 25 Hz or more than 250 Hz?!? This indicates massive problems with VBL sync. ----- ! 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. ---
**Author:** ![mariokleiner](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@mariokleiner](https://psychtoolbox.discourse.group/u/mariokleiner)\ **Post date:** [May 19, 2008, 9:14pm UTC](https://psychtoolbox.discourse.group/t/errors-with-vblsynctest-and-screen-39-flip-39/1975/2 "2008-05-19T21:14:08Z")
Card isn't syncing to vertical retrace, because the driver prevents it/its disabled... 1. Open the Catalyst Control Center panel (display settings). 2. In the "3D settings" subsection, look for a control slider or such that is called "Wait for vertical refresh" or similar. Make sure it is set to "Application controlled, default to on" or similar. I guess yours is set to "always off" or similar? If that doesn't help, follow the thread of messages around message 8013 that describes a similar problem with the Radeon 2600 XT on Vista. -mario > --- In [psychtoolbox@yahoogroups.com](mailto:psychtoolbox@yahoogroups.com), "yingyang215" \ wrote: > \> > \> I am on a Toshiba Satellite P-200 with ATI Mobility Radeon 2600 4Gb > \> Ram Vista Ultimate. I was trying to do the very first tutorial and I > \> cannot even open the window without having errors. I have tried > \> everything I could find. I fixed the beamposition error by disabling > \> my antivirus but still cannot get anything on VBLsync or get anything > \> with Screen('Flip'). Thanks > \> David > \> > \> > \> \>\> VBLSyncTest() > \> > \> screenwidth = > \> > \> 1680 > \> > \> > \> screenheight = > \> > \> 1050 > \> > \> > \> > \> PTB-INFO: This is the OpenGL-Psychtoolbox for Microsoft Windows, > \> version 3.0.8. (Build date: Apr 16 2008) > \> PTB-INFO: 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\_depth\_texture GL\_ARB\_draw\_buffers > \> GL\_ARB\_fragment\_program GL\_ARB\_fragment\_shader GL\_ARB\_multisample > \> GL\_ARB\_multitexture GL\_ARB\_occlusion\_query GL\_ARB\_point\_parameters > \> 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\_float GL\_ARB\_texture\_mirrored\_repeat > \> GL\_ARB\_texture\_non\_power\_of\_two 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\_ATI\_draw\_buffers GL\_ATI\_envmap\_bumpmap GL\_ATI\_fragment\_shader > \> GL\_ATI\_meminfo GL\_ATI\_separate\_stencil GL\_ATI\_texture\_compression\_3dc > \> GL\_ATI\_texture\_env\_combine3 GL\_ATI\_texture\_float 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\_copy\_texture 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\_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\_subtexture 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\_add 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\_KTX\_buffer\_region GL\_NV\_blend\_square GL\_NV\_texgen\_reflection > \> GL\_SGIS\_generate\_mipmap GL\_SGIS\_texture\_edge\_clamp > \> GL\_SGIS\_texture\_lod GL\_WIN\_swap\_hint WGL\_EXT\_swap\_control > \> > \> PTB-ERROR: Mismatch between requested display swap interval 1 and > \> actual swap interval 0! Synchronization of Screen('Flip') to display > \> refresh will likely malfunction! > \> PTB-ERROR: This is either a bug in your graphics driver or system > \> setup, or some misconfiguration in the display setting control panel > \> of your system. See 'help SyncTrouble' for more info. > \> PTB-WARNING: Couldn't even collect one single valid flip interval > \> sample! Sanity range checks failed! > \> PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL > \> sync failure! > \> PTB-WARNING: Couldn't even collect one single valid flip interval > \> sample! Sanity range checks failed! > \> PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL > \> sync failure! > \> PTB-WARNING: Couldn't even collect one single valid flip interval > \> sample! Sanity range checks failed! > \> PTB-WARNING: Couldn't collect valid flip interval samples! Fatal VBL > \> sync failure! > \> > \> > \> PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Mobility > \> Radeon HD 2600 :: 2.0.6479 Release > \> PTB-Info: VBL startline = 1050 , VBL Endline = 1095 > \> PTB-Info: Measured monitor refresh interval from beamposition = > \> 17.009855 ms [58.789449 Hz]. > \> PTB-Info: Will use beamposition query for accurate Flip time stamping. > \> PTB-Info: Measured monitor refresh interval from VBLsync = 0.000000 > \> ms [1.#INF00 Hz]. (0 valid samples taken, stddev=1000000000.000000 > \> ms.) > \> PTB-Info: Reported monitor refresh interval from operating system = > \> 16.949153 ms [59.000000 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?!? > \> > \> WARNING: Mismatch between measured monitor refresh interval and > \> interval reported by operating system. > \> This indicates massive problems with VBL sync. > \> > \> WARNING: Measured monitor refresh interval indicates a display > \> refresh of less than 25 Hz or more than 250 Hz?!? > \> This indicates massive problems with VBL sync. > \> > \> > \> ----- ! 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. > \>