# Can I used Three External USB Video Cards for 3 separate screens in Qlab?



## rossgrahamdesign (Apr 5, 2012)

Can I used 3 USB External Video cards to Q video to different video sources in Qlab. I am curious is the MacBook will or Qlab with see the usb Externals and if the will work. I am needing to send video to a B&W TV that flys in, A set tv, Front Projector.

Thoughts?


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## joeladria (Apr 9, 2012)

This will depend mostly on the power of your MacBook. Most MacBooks with integrated graphics won't perform this very well, if at all. What sort of MacBook are you using, and what USB graphics cards do you have in mind?


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## tyler.martin (Apr 12, 2012)

joeladria said:


> This will depend mostly on the power of your MacBook. Most MacBooks with integrated graphics won't perform this very well, if at all. What sort of MacBook are you using, and what USB graphics cards do you have in mind?



I would suggest skipping the USB video card option and look at a Matrox TripleHead2Go. USB video devices tend to have quite a bit of a bandwidth overload when playing video clips. I even had trouble finding ones that worked with Mac OS Lion. 

The Matrox card will use the existing video output of your Mac but trick it into thinking its 3 screens. I've used mine with both my white plastic MacBook with inboard graphics and my MacBook pro with dedicated graphics, playing HD video, with no problem. Keeping in mind you need the pro video license with Qlab.


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