DVI vs VGA

imacfanimacfan
Posted:
in Current Mac Hardware edited January 2014
Hi,



As you might know by now, I'm on the brink of getting a PB 12". I just wondered if any of you know just how much difference there is between a DVI signal and a VGA signal's quality when hooked up to an LCD display? For instance, does the VGA signal cause any flicker, despite the LCD?



Thanks,



David

Comments

  • Reply 1 of 6
    dfilerdfiler Posts: 3,420member
    IMHO, the biggest difference is ghosting. DVI eliminates ghosting introduced by monitor cables running close to other wiring.
  • Reply 2 of 6
    gspottergspotter Posts: 342member
    On the other hand, my G4 (MDD 2x1 GHz) has problems with my Monitor (Iiyama 17.4'' LCD with DVI and VGA input) when I connect it via DVI. With VGA, everything is fine, with DVI, whenever the computer wakes from sleep, I get some moving artefacts (flickering pixels) on the screen. This happens (reproduceable) only after wake from sleep. Right after booting, DVI works fine for me.
  • Reply 3 of 6
    stoostoo Posts: 1,490member
    The PowerBook's video out is classed as RGB out, with VGA and Composite/S Video adpators. Is this similar to the RGB ports on some TVs/consoles/etc?
  • Reply 4 of 6
    aquaticaquatic Posts: 5,602member
    Yes. That is why the adapter is there, to plug in to a TV or other component.
  • Reply 5 of 6
    stoostoo Posts: 1,490member
    It's decribed as "compatible with the Hosiden TCX3143" at Apple's Developer site, but I can't find any further info on that connector. The PowerBook detects which adpator is plugged (using DDC) in and varies the output accordingly. The display ID for S-Video/Composite devices is stored on the adpator.



    RGB video uses a separate cable for each of the RGB components of video, so it's closer to VGA than S-Video or Composite video out. It looks like it would be possible in theory, but not without an adaptor.
  • Reply 6 of 6
    shetlineshetline Posts: 4,695member
    Quote:

    Originally posted by iMacfan

    I just wondered if any of you know just how much difference there is between a DVI signal and a VGA signal's quality when hooked up to an LCD display? For instance, does the VGA signal cause any flicker, despite the LCD?



    What suffers the most is the sharpness of the image. A DVI signal can be precisely mapped from video memory pixels to physical display pixels,which gives you as sharp an image as the display pixels can provide.



    VGA, however, is an analog signal, and the signal doesn't have any precisely encoded pixel boundaries. Each memory pixel only lands more or less where is should be on the physical display, smeared out a bit over more than one display pixel.
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