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I have a standard VGA splitter connected to a nvidia nforce 631i on ubuntu 9.04. However, when the splitter is in use, the image gets dark. If I unplug one cable, it doesn't. this phenomenon is noted elsewhere on the net, but no solution.

I think this could be fixed by increasing the "power output" of the video card, which may involve overclocking or tweaking the voltage, but I know little about this.

Any thoughts?


I'm aware of powered VGA splitters, but I'm trying to make it work with the unpowered one I bought.

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up vote 5 down vote accepted

I don't think overclocking or tweaking your card will make any difference and "increasing the power output of the card" will possibly destroy your monitor. What you need is probably a powered VGA splitter that will replicate and repeat the signal to the other monitor rather than just passively split it.

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And, whatever you do, don't daisy chain the splitters. You could burn something out with more than two monitors. – Dennis Williamson Jul 24 '09 at 15:47

Ditch the VGA wye cable and get yourself a good powered VGA splitter.

We just bought fifty or so of the StarTech ones. They are amazing!

  • The monitor returns to full brightness and all distortion is alleviated.
  • The projector's output is sharpened and returns to full brightness as well.

They're USB powered, so:

  • There is no wall-wart to waste an outlet or get in the way.
  • No power being used when the computer is turned off.

They only cost us about $18 USD apiece in bulk, and are worth every cent.

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If the video card has both dvi and vga outs, you can use the dvi out as a vga source with a cheap adapter - no need to split.

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The DVI output is already used for a dual-monitor setup (twinview). I'm trying to mirror one of them onto the TV. – Paul Biggar Jul 24 '09 at 14:57
But, now that you mention it, I might be better off splitting the DVI than splitting the VGA. – Paul Biggar Jul 24 '09 at 14:58

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