# Multiple Display sync issue; A hardware problem?

**URL:** <https://psychtoolbox.discourse.group/t/multiple-display-sync-issue-a-hardware-problem/619>\
**Category:** Uncategorized\
**Created:** [January 19, 2012, 9:45pm UTC](https://psychtoolbox.discourse.group/t/multiple-display-sync-issue-a-hardware-problem/619 "2012-01-19T21:45:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**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:** [January 19, 2012, 9:45pm UTC](https://psychtoolbox.discourse.group/t/multiple-display-sync-issue-a-hardware-problem/619/1 "2012-01-19T21:45:01Z")

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Hello,  
  
I am trying to use two displays with psychtoolbox. When I try to open  
a screen on the secondary display I receive error messages stating  
there is a synchronization failure, and "couldn't even collect one  
single valid flip interval sample!"  
  
 I am using Psychtoolbox version 3.0.9 - Flavor: beta - Corresponds to  
SVN Revision 2434, and matlab version 7.13 (R2011b). I am running on  
Windows XP.  
  
I have tried everything stated in 'help SyncTrouble' without solving  
the error. It seems like the most likely culprit is my graphics  
hardware, Intel Processor Graphics 2000. I am considering replacing it  
with one of the recommended Direct3D-10/11 capable graphics cards.  
  
Before I do, is this likely to solve the sync problems? Is there  
anything else I should try?  
  
Thank you for any response,  
  
Lisa Pritchett  
PhD Student in Psychology,  
Harris Multisensory Integration Lab: yorku.ca/harris  
York University, Toronto

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<div class="post-metadata">

**Author:** ![mariokleiner](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@mariokleiner](https://psychtoolbox.discourse.group/u/mariokleiner)\
**Post date:** [January 20, 2012, 1:05pm UTC](https://psychtoolbox.discourse.group/t/multiple-display-sync-issue-a-hardware-problem/619/2 "2012-01-20T13:05:35Z")

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Try to select some "Extend desktop horizontally" mode, instead of "Separate Monitors" or however this is called in the display settings panel. If ptb only sees one screen (0) in Screen('Screens') instead of 3 different screens, that's usually more reliable on Windows. You'd open one onscreen window covering both displays, use stereomode 4 or 5 for the left-eye / right-eye stimulus. Also make sure the framerate settings and resolutions on both monitors match. Try if assigning one or the other monitor as "primary monitor" makes a difference.  
  
I don't have any experience with modern Intel gpu's, but at least on paper it should be good enough.  
  
-mario  
  

> --- In [psychtoolbox@yahoogroups.com](mailto:psychtoolbox@yahoogroups.com), Lisa Pritchett \<p.lisamarie@...\> wrote:  
> \>  
> \> Hello,  
> \>   
> \> I am trying to use two displays with psychtoolbox. When I try to open  
> \> a screen on the secondary display I receive error messages stating  
> \> there is a synchronization failure, and "couldn't even collect one  
> \> single valid flip interval sample!"  
> \>   
> \> I am using Psychtoolbox version 3.0.9 - Flavor: beta - Corresponds to  
> \> SVN Revision 2434, and matlab version 7.13 (R2011b). I am running on  
> \> Windows XP.  
> \>   
> \> I have tried everything stated in 'help SyncTrouble' without solving  
> \> the error. It seems like the most likely culprit is my graphics  
> \> hardware, Intel Processor Graphics 2000. I am considering replacing it  
> \> with one of the recommended Direct3D-10/11 capable graphics cards.  
> \>   
> \> Before I do, is this likely to solve the sync problems? Is there  
> \> anything else I should try?  
> \>   
> \> Thank you for any response,  
> \>   
> \> Lisa Pritchett  
> \> PhD Student in Psychology,  
> \> Harris Multisensory Integration Lab: yorku.ca/harris  
> \> York University, Toronto  
> \>