Author Topic: Someone explain Displayport to me  (Read 589 times)

Offline Cobra951

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Someone explain Displayport to me
« on: Monday, December 12, 2016, 02:35:42 PM »
So I'm looking at computers, and my display, being 10 years old, can only do VGA for PC input.  (HDMI input is restricted to standard HDTV resolutions.)  The Nvidia card in what I'm considering does HDMI, DVI and something called "Displayport", which is apparently universal.  I found this, which looks like a simple passive adapter.  But someone told me that Displayport is digital, which would seem to imply the need for an active converter to VGA analog (R,G,B, HSync, VSync).  Any words of wisdom?  This is all new to me.  I have way too much stuff connected to this screen through all manner of modern and legacy inputs.  Replacing it would be a serious endeavor, even if money were no object (which it definitely is).  So the lack of a solution here is probably a deal breaker on the PC.
« Last Edit: Friday, December 16, 2016, 03:50:38 PM by Cobra951 »

Offline Cobra951

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Re: Someone explain Displayport to me
« Reply #1 on: Tuesday, December 13, 2016, 05:50:40 AM »
I guess I can.  That would imply that either the Displayport carries the analog signals, or the "adapter" is really a DA converter.  I'm not a fan of the latter.  If there's a return policy on the PC, I think I may try my luck with it.

Offline scottws

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Re: Someone explain Displayport to me
« Reply #2 on: Tuesday, December 13, 2016, 07:27:19 AM »
DisplayPort is indeed pretty universal.  It's generally the port (in Mini DisplayPort form) you've seen for external display output on ultrabooks for the last several years, though larger laptops (especially consumer versions) sometimes have both it and HDMI.  That said, the connector is starting to be replaced by USB-C because the USB type C spec has support for Alternate Modes, including DisplayPort.

DisplayPort is a digital specification, so any DisplayPort to VGA adapter must have a DAC.  Or at least that's the only way I imagine that they'd be able to work.

Offline Cobra951

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Re: Someone explain Displayport to me
« Reply #3 on: Tuesday, December 13, 2016, 09:26:01 AM »
Yeah, I've since read some disheartening news about Nvidia and others pretty much abandoning VGA since last year.  I need to think more about this.  A DAC would introduce lag, and almost surely degrade the signal, perhaps even prevent me setting the native panel resolution.  I may go with a more basic system with legacy support and give up on gaming capabilities.  I'm doing all gaming on console now anyway.  It was just a thought.

I do have this cheap ACER monitor with a DVI-D connection, though.  I'd need to rearrange my desktop to use it, since it's off to the side as a 2nd PC screen for when I'm using something else on the main screen.

Offline Cobra951

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Re: Someone explain Displayport to me
« Reply #4 on: Friday, December 16, 2016, 03:49:38 PM »
It worked!  1080p (max) DisplayPort-to-VGA converter discovered the make (Samsung) and panel resolution (1366x768) of my all-purpose screen, and it painlessly came up at the right resolution right off the bat.  So we're all good here.

Offline scottws

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Re: Someone explain Displayport to me
« Reply #5 on: Saturday, December 17, 2016, 12:08:09 PM »
Nice! Glad it worked out.

Offline MysterD

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Re: Someone explain Displayport to me
« Reply #6 on: Sunday, February 05, 2017, 06:05:54 PM »
Linus on differences b/t VGA, DVI, HDMI, and DisplayPort:


I currently have my 4K screen 27'' Samsung monitor for my desktop connected via DisplayPort, since the DisplayPort cable that came w/ it does 4K @ 60hz.
HDMI cable that came w/ my screen only does 4K @ 30hz.

Newest HDMI 2.0 cable does 4k @ 60z, but next version of DisplayPort 1.3 will be able to do 8K @ 60hz.

Personally, I'm digging DisplayPort. :)

Offline Cobra951

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Re: Someone explain Displayport to me
« Reply #7 on: Sunday, February 05, 2017, 10:17:15 PM »
Thanks for that.  I didn't know DP was so much better than HDMI (current 1.4 standard).  My card has 3 (three!) DP ports, a DVI and an HDMI. 

I recently edited my long post in my PC thread to describe how much quality I gained on my VGA connection by taking a VGA switchbox and 2nd VGA cable out of the loop.  It was there since my eMachines crap PC which ended up frying itself so dramatically that sparks were visible around the power switch.  (Yes, I witnessed that firsthand.)  That happened, what, about 8 years ago?  All this time I had my good PC, the Dell Dimension 8100, hooked up through the switchbox.  It looked fine.  The issue with the other connection to the box (used initially with my new PC) was that the cable from the box to the screen VGA port followed the same path as the cable from the PC to the box.  So the crosstalk was causing obvious ghosting, and a loss of sharpness that I was attributing to a cheap DAC in the DP-VGA converter.  As soon as I connected the new PC directly to the VGA screen port, all that degradation went away.  It now looks sharp and clean, even better that the Xbox One hooked up through HDMI (@720p).  There's nothing wrong with VGA at this resolution (768p native) with the proper hookup, and there's nothing wrong with this DP-VGA converter either.

It would be nice to get a DP or HDMI audio and video digital connection to a great monitor.  That will have to wait, and I will not be unhappy in the interim.  I am really pleased with my setup right now.

Offline Xessive

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Re: Someone explain Displayport to me
« Reply #8 on: Thursday, March 16, 2017, 11:43:12 AM »
I got my 144Hz monitor before I had a card with DisplayPort, so I could never take advantage of the screen rate, since I was connecting using HDMI at the time I was limited to 60Hz and I never bothered to get a DVI-to-DisplayPort converter.

I didn't realize what I was missing out until I finally connected my monitor to my newly built rig (at the time) and dragged a window across the screen. I had a "woah" moment noticing there was something surprisingly smooth about it.