# Timing with video splitter

**URL:** <https://psychtoolbox.discourse.group/t/timing-with-video-splitter/1391>\
**Category:** Uncategorized\
**Created:** [December 2, 2009, 5:15pm UTC](https://psychtoolbox.discourse.group/t/timing-with-video-splitter/1391 "2009-12-02T17:15:45Z")\
**Posts on this page:** 1\
**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:** [December 2, 2009, 5:15pm UTC](https://psychtoolbox.discourse.group/t/timing-with-video-splitter/1391/1 "2009-12-02T17:15:45Z")

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Hi everyone,  
  
I want to send the images from my video card to two monitors: one inside   
our recording chamber (for the subject) and one to a monitor outside the   
chamber (for the experimenter). The monitor inside the chamber will be a   
fast CRT monitor while the monitor outside will be a slow TFT. The   
low-budget solution would be to connect the video card to a   
VGA-splitter, which in turn is connected to the two monitors.  
  
My question is: how is timing handled in this situation? Can I still   
present stuff on the CRT monitor at a fast rate (say 120 Hz) with   
reliable synchronization with the CRT vertical refresh? Timing on the   
TFT does not really matter, and it does not need to be in precise sync   
with the CRT.  
  
Or would a dual output video card solve the problem?  
  
Any help is appreciated!  
Niko