Re: Dual mode display port to DVD-D adapter?

Paul <[email protected]> wrote in news:[email protected]:

> On 9/13/2022 11:40 PM, Boris wrote:
>> I received a Dell 8950, 12th gen i7, with a onboard graphics.  The 
display
>> port is:
>> 
>> Dual-Mode DisplayPort 1.4
>> Connect an external display or a projector.
>> NOTE: Besides a DisplayPort connector, this port can also provide 
display
>> output to a DVI or HDMI connector with a
>> DisplayPort 1.4 adapter (sold separately).
>> 
>> None of the monitors I have hanging around have HDMI.  They do have 
DVD-D.
>> Is there such a thing as a dual mode display port to DVD-D adapter.  Is 
so,
>> can you recommend a decent one?
>> 
>> I don't do gaming or video editing.
>> 
>> TIA
>> 
> 
> You have to check the details on the product, to make
> sure it's the right one for the monitor. Many monitors
> will be 1920x1080 @ 60Hz, and either adapter below would work.
> An Apple Cinema monitor, one of the old ones, might require
> the expensive adapter, as the Cinema monitor was dual link.
> It's one DVI connector, but there are two "sets" of pins,
> each one is termed to be a "link".
> 
> DP to DVI single link $20   [ 1920x1080 or 1920x1200 CRTRB ? ]
> https://www.startech.com/en-us/audio-video-products/dp2dvi2
> 
> DP to DVI dual link  $163   [ 2560x1600 or higher ]
> https://www.startech.com/en-us/audio-video-products/dp2dvid2
> 
> I've put a notation next to the "most taxing" display mode.
> Displaying at 30Hz or even 24Hz, is OK for movie night, but
> not so good for normal monitor usage. That's why 60Hz is
> a better metric, than pretending that 24Hz is impressive or something.
> The DVI clock interface cannot go over 165MHz. On the cable
> this is multiplied by 10, and is actually 1650MHz. You can
> see the 2560x1600 @ 60Hz, the adapter is "loafing along" at
> only 135MHz.
> 
> https://en.wikipedia.org/wiki/Digital_Visual_Interface
> 
>     "Example display modes (single link):
> 
>      SXGA (1280 × 1024) @ 85 Hz with GTF blanking (159 MHz)
>      HDTV (1920 × 1080) @ 60 Hz with CVT-RB blanking (139 MHz)
>      UXGA (1600 × 1200) @ 60 Hz with GTF blanking (161 MHz)
> 
>      WUXGA (1920 × 1200) @ 60 Hz with CVT-RB blanking (154 MHz)  
154<165max
> 
>      WQXGA (2560 × 1600) @ 30 Hz with CVT-RB blanking (132 MHz)
> 
>      Example display modes (dual link):
> 
>      QXGA (2048 × 1536) @ 72 Hz with CVT blanking (2 × 163 MHz)
>      HDTV (1920 × 1080) @ 144 Hz[6]
>      WUXGA (1920 × 1200) @ 120 Hz with CVT-RB blanking (2 × 154 
MHz)
> 
>      WQXGA (2560 × 1600) @ 60 Hz with CVT-RB blanking (2 × 135 
MHz)  135<165max
> 
>      WQUXGA (3840 × 2400) @ 30 Hz with CVT-RB blanking (2 × 146 
MHz)
>     "
> 
> DVI single link, half the digital pins are working at the time.
> DVI dual link, all the digital pins are working, to achieve the
> higher resolution. And this is due to the DVI spec being moribund
> and stopping at 165MHz. When clock rates have been climbing since
> then (for HDMI and DP) and allowing much higher resolutions. There
> is less interest (apparently), in making dual link DVI items. Maybe
> it took two adapter chips rather than just one. You never know.
> Some of these chips are re-purposed adapter chips used in TV sets
> (on the TV set IO board). That is why some of them are so cheap.
> 
>     Paul
> 
> 

Thanks for the reply.

The connector looks like a DVI-I dual link connector, with it's 3x8 block 
of pinouts and the other four pinouts.  Can I assume that a dual link DVI-
I connector is used on all StarTech's display port converter cables, but 
not all pins are wired, depending on it's intended use?  Or is the picture 
incorrect?

(You may notice that I'm posting on aioe.org, instead of E-S.  For some 
unknown reason, to me, E-S gave me a 441: Excessive nymshifting.  I rarely 
post, but read a lot.  I've probably posted three times in the last week.  
I did read on Narkive that there was a discussion of E-S probably turning 
on nymshifting discipline measures about a month ago.)