VGA v DVI difference

  Terry Brown 10:50 18 Feb 2009

What is the difference between a standard 'D Sub' VGA output and a DVI (Digital output) in terms of pixel size/ clarity.
My computer has both, and I am looking for a new monitor

Some monitors are SXGA and some VGA, I presume SXGA being an oblong pixel is for Widescreen Monitors and VGA for standard 'square' monitors, or am I wrong.
All advice thankfully recieved.

Thank you

  GANDALF <|:-)> 11:15 18 Feb 2009

My monitor and computer both have VGA and DVI and I have used both. I have eyes like a ferret on speed and I cannot tell the difference.


  Spark6 11:22 18 Feb 2009

You've made my day! I don't *have eyes like a ferret on speed*, mine are full of laughter tears. Brilliant.

  HighTower 11:24 18 Feb 2009

I do find DVI much clearer, and in particular it displays much less interference. I noticed that sometimes when using VGA a small amount of banding in solid colours was evident moving up and down the screen when I used the mouse. A better cable with good insulation made a noticeable difference, but DVI eliminates it completely.

  gazzaho 11:33 18 Feb 2009

I would imagine the image quality would only perhaps be apparent when converting from VGA to DVI as you would be going from an analog to digital signal and the conversion may degrade the image quality.

  DieSse 16:29 18 Feb 2009

Internally on a graphics card, the signals are digital - the DVI output keeps them as digital to send to the monitor. The VGA output has a converter to turn them into analogue signals.

LCD monitors work internally in digital (CRTs only work in analogue) - so on the VGA input there is another converter to turn the analogue back into digital.

As you can thus see - if you use DVI at both ends, it avoids the signals being converted to analogue, going down a cable, then being converted back again.

Clearly in principle, avoiding two unnecessary conversions has to result in better, cleaner signals.

However, as Gandalf said - modern moniotrs are quite good at handling analogue signals, so in many cases it's difficult to see a difference in practice.

Note that it's only DVI to DVI that can have any benefit - any converters anywhere destroy the potential benefit.

If you can get a monitor with both DVI and VGA, however, firstly it's future-proofed (if your current card only has VGA - your next one might have DVI) - and secondly, you can share the monitor easily between two systems if you need to, switching between them on the monitors own controls.

  Terry Brown 19:44 23 Feb 2009

Thank you all for your advice.
I have now chosen HANNS.G HQ191D 19" DVI TFT monitor.

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