Displayport vs DVI

[Martin Racette]

Hi,

I would like to know which one is the best to connect a 27" LCD monitor, I
am considering 2 Asus VE278Q, and I am mostly using Office 2010, Microsoft
Flight Simulator 10, and Civilisation V

BTW. I am currently using 2 Samsung 24" connected to 2 cross-fired ATI
HD6950

--
Thank you in advance

Merci a l'avance

Martin

 

[Paul]

Hi,

I would like to know which one is the best to connect a 27" LCD monitor,
I am considering 2 Asus VE278Q, and I am mostly using Office 2010,
Microsoft Flight Simulator 10, and Civilisation V

BTW. I am currently using 2 Samsung 24" connected to 2 cross-fired ATI
HD6950

They're both digital, so should not degrade the image.

*******

How did you select that particular Asus ? Will you be buying two of them ?
The reviews on Newegg, note a particular failure mode.
"screen flashing and going blank issue"

http://www.newegg.com/Product/Product.aspx?Item=N82E16824236103

The Asus user manual mentions:

Display Colors 16.7M (6bit Hi FRC)

implying colors are done via temporal dithering. The Newegg
reviews don't note any artifacts from that. FRC is explained here
a bit. What a "Hi FRC" is, only Asus knows I guess.

http://en.wikipedia.org/wiki/Frame_Rate_Control

http://www.xbitlabs.com/articles/monitors/display/lcd-guide_11.html

Paul

 

[Martin Racette]

I selected it because that is the only one available that has Displayport on
it, and yes I would be installing 2 of them

 

[Paul]

I selected it because that is the only one available that has
Displayport on it, and yes I would be installing 2 of them

I did find another issue with DisplayPort, but this thread is
a bit old now.

http://www.avsforum.com/avs-vb/showthread.php?t=1051135

The thing is, DisplayPort does have a content protection option,
but it involves a license to the inventor of it, unlike the
baseline parts of DisplayPort which don't involve paying
royalties. Which raises the question of whether it is included
by default or not.

On HDMI, HDCP is the content protection mechanism. Windows
relies on such schemes, when driving high res monitors. In
the more modern OSes, the output to the screen can be
modified (reduced effective resolution), if a monitor doesn't
have a content protection mechanism.

So if I was to use VGA and drive a 1920x1080 VGA equipped
monitor, I would logically expect Windows to make my
movie playback look crappy.

So when you eventually get your new monitor, check to see
whether playback under HDMI/HDCP, looks the same as DisplayPort.
From a digital perspective, either standard should be able
to send bit-perfect images to the screen. But the OS response
to the monitor infrastructure, is a separate issue.

http://en.wikipedia.org/wiki/Protected_Video_Path

http://en.wikipedia.org/wiki/Certified_Output_Protection_Protocol

It looks like Content Protection is supported in DisplayPort 1.1 or
later, as in:

http://en.wikipedia.org/wiki/Displayport

128-bit AES DisplayPort Content Protection (DPCP) support, and
support for 40-bit High-bandwidth Digital Content Protection
(HDCP) from version 1.1 onwards.

but I presume the latter option is when using something like a
DisplayPort to HDMI adapter or the like. There is still some
wiggle room there, to end up with no content protection. And the
latest Windows OSes (Vista and Windows 7), already have tamper
proofing in the video driver section, which is bad enough (as
there is a danger that tamper proofing can trigger, when
no tampering is occurring).

What the above means is:

1) When you get your new monitor, do an A:B comparison between
the two paths, and see whether there are any deficiencies. I
don't know if the color space is handled the same way, and whether
there will be differences in what you see in that sense. But if
you see a "lack of sharpness" in the image, Windows could be
doing that. I also don't know if there is anything in the
Windows user interface, to declare a path is protected or not.

HTH,
Paul