Author Topic: Is HDMI supposed to look worse?  (Read 602 times)

Afkpuz

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Is HDMI supposed to look worse?
« on: March 09, 2009, 02:37:41 am »
Hey all, right now, I'm using a VGA interface @720p for LMCE and couldn't be happier.  However, I did dabble with HDMI for a while since my lcd tv has both vga and hdmi.  I noticed that both in LMCE and in ubntu (never tested in windows), the picture looks worse when I use a DVI>HDMI cable.  I've tested with different cables too.  Everything is alot less clear using HDMI.  Font shrinks and are unreadable. Pixels also seem alot bigger and blockier, even though I run at the same resolution as VGA.  I don't feel the need to correct this, I just want to understand why this happens.  Why does quality degrade so much?  Shouldn't quality go up?  Does anyone else experience this? 

colinjones

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Re: Is HDMI supposed to look worse?
« Reply #1 on: March 09, 2009, 04:07:47 am »
HDMI and DVI (these are identical for video signal) are much better quality than VGA. You are describing an actual change in the image "mode" and fonts rather than simple distortion of the same image. This could either be because the mode generated by your card is different in response to using a different connector or the screen rescaling the image... check the xorg.0.log for the mode timings with each cable to confirm the former, first....

donpaul

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Re: Is HDMI supposed to look worse?
« Reply #2 on: March 09, 2009, 05:57:45 am »
VGA is analog, basically RGB with some other data thrown in. DVI can be both Analog and digital. HDMI is pure digital, with no loss in quality. You can't convert an analog DVI to HDMI. I would suggest using VGA, unless you convert DVI-D to HDMI, and are sure your GPU and TV are both configured correctly.

720p looks the same for the most part with either VGA or HDMI, but it really depends on the TV. But you will need HDMI (and a good GPU) if you want 1080p.
« Last Edit: March 09, 2009, 05:59:26 am by donpaul »