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Re: Video Cables Question

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On 7/6/2015 at 3:16:08 PM Paul wrote:

> 
> DisplayPort cables exist in two types.
> 
> 1) Passive (cheap)
> 2) Active (expensive)
> 
> The necessity of each, depends on what is at
> each end of the cable. For example
> 
>    DisplayPort --> VGA   (active, expensive)
> 
> So what you want to do, is price cables, and
> see if DisplayPort to DVI is a cheap cable.
> 
> Note that if it is a cheap cable, it would
> have DVI-D on output. The DVI-I connector has
> an analog (VGA) and a digital (DVI-D) section,
> and if there is such a thing as a cheap
> DisplayPort to DVI cable, it just has the
> digital signals on it. Which is perfectly
> fine. The only reason for my warning, is
> if you attempt to combine a
> 
>    DisplayPort --> DVI-D    +    DVI to VGA dongle
> 
> there would be no signal on the VGA pins.
> 
> So in general terms, it's possible for a
> DisplayPort to make digital signals without
> too much fuss. But some formats, such as VGA,
> an active chip inside the fat end of the cable,
> does a translation for you. And that costs
> money. And might even need a small power adapter
> plugged into the wall.
> 
> *******
> 
> DisplayPort to DVI will look superior at the
> limits of resolution. Say, for example, the
> DisplayPort does "single link DVI", which has
> a 1920x1200 reduced blanking limit. Well, the
> picture from that would be sharp as a tack.
> Whereas, if you asked the VGA port on some
> computer, to make 1920x1200, it's not going
> to be nearly as nice.
> 
> At lower resolutions, you would be hard pressed
> to tell the difference. At 1024x768, they would
> look the same. But as the native resolution requirement
> goes up (driving big-ass monitor), then the DisplayPort
> to DVI digital method looks better.
> 
> *******
> 
> OK, so let's go shopping :-)
> 
> Coboc 6 inch DisplayPort to DVI Passive Adatper   $8
> http://www.newegg.com/Product/Product.aspx?Item=N82E16812119558
> 
>    "Requires a Dual-mode DisplayPort(DP++) Source"
> 
> So the price tells you it is a passive converter.
> 
> And the technical requirement in the advertisement,
> tells you what to check for on the video card end.
> 
> If the video card is DP++, then it can drive the
> eight dollar adapter for you. And provide
> single link DVI up to 1920x1200 @ 60Hz
> 
> So before you spend $8, start researching the
> DisplayPort source characteristics (on your
> video card).
> 
>    Paul

Thanks Paul.

The desktop is a Dell OptiPlex 9020 Mini Tower with an Intel i7-4790
processor, so the Intel HD Graphics 4600 within the i7-4790 takes care
of the video signal.  The desktop has no discrete video card.

According to this link:
<http://ark.intel.com/products/80806/Intel-Core-i7-4790-Processor-8M-Cac
he-up-to-4_00-GHz>, the graphics autput is DP (not DP++), and I was
thinking about purchasing this cable:
<http://www.monoprice.com/Product?c_id=102&cp_id=10246&cs_id=1024608&p_id=6015&seq=1&format=2>.

What do you think?
-- 
tb

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Video Cables Question "tb" <nospam@example.invalid> - 2015-07-06 19:56 +0000
  Re: Video Cables Question Paul <nospam@needed.com> - 2015-07-06 16:16 -0400
    Re: Video Cables Question "tb" <nospam@example.invalid> - 2015-07-06 20:40 +0000
      Re: Video Cables Question Paul <nospam@needed.com> - 2015-07-06 18:35 -0400

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