[mythtv-users] Artifacts on screen with DVI to HDMI cable

ryan patterson ryan.goat at gmail.com
Mon Jun 25 13:35:14 UTC 2007

On 6/25/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> On 06/24/2007 11:05 PM, David Cramblett wrote:
> > This turned out to be the MSI FX5200 Video card.  It just couldn't run
> > either the 15' cable length or it doesn't like the DVI->HDMI cable, I
> > don't know which. However, 15' VGA -> RGB Component worked fine.
> DVI cables were designed to be cheap to manufacture, rather than being
> designed to carry the DVI signal (SDI), so they are actually far more
> sensitive to long cable runs than are VGA cables or component cables.
> HDMI cables are typically even worse (because--in addition to having the
> same design flaw as DVI cables--the cables tend to be smaller gauge).
> Some cable manufacturers do different things to work around the inherent
> weakness of the design (often adding significantly to the cost of the
> cables).  Whether their techniques work, I couldn't tell you--I'm also
> using VGA happily.  TTBOMK, no cable manufacturer has actually created a
> "proper" cable for DVI/HDMI.  (SDI is designed to be carried over
> coaxial wires, but DVI/HDMI uses twisted pair.  I don't know of any
> source of DVI/HDMI cables using coaxial wires.)
> Mike

Sorry Mike you are 100% wrong.  SDI signaling is not the same as DVI or HDMI
signaling.  TMDS signaling used for DVI and HDMI is designed for twisted
pair cabling not coaxial.  Using coaxial cables and BNC jacks for a TMDS
signal would be absurd.  There is no inherent design weakness in the
DVI/HDMI cable designs.  Also the video part of the HDMI standard is 100%
compatible with DVI.  So there are no issues when manufacturers make HDMI to
DVI cables.  The digital signals used in DVI/HDMI are much better suited to
longer cable runs then VGA or component signals.

Ryan Patterson
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-users/attachments/20070625/54fc25bd/attachment.htm 

More information about the mythtv-users mailing list