dual link DVI?

[Doom9]

Perhaps you've read about the latest Apple flatscreen panels: http://www.apple.com/displays/. The 30" one is really sweet, at a native resolution of 2560 x 1600, even HDTV is too small to fill the screen ;)

Apple says you need a special GFX card with a DDL (DVI Dual Link) interface to connect the card. I've never heard the term, but the card (there's no closeup) that is supposed to feed that display looks like it has two standard DVI connectors, and since you can connect two such panels to that nVidia card, one connector is for one screen. So I'm a bit puzzled. Is standard DVI limited to certain resolutions? When I started out with flatpanels I thought it would only go up to 1280x1024 (all higher res displays only supported high resolutions via analogue input), but since then I've used a 1600x1200 and 1920x1200 display connected via DVI and things worked out fine. Does anybody have more info on DDL and why a standard DVI interface would not be enough for that 30" screen?

[smiller667]

Dual Link DVI supports 2x165 MHz (2048x1536 at 60 Hz, 1920x1080 at 85 Hz). A dual link implementation utilizes all 24 of the available pins.

Single Link DVI supports a maximum bandwidth of 165 MHz (1920x1080 at 60 Hz, 1280x1024 at 85Hz). A single link implementation utilizes 12 of the 24 available pins.

Source http://www.ddwg.org/dvi.html

[edited to fix the link]

[Koepi]

Damn. yesterday I spent my hard earned money on a 19" tft with dvi-input just to read now that i'm using oooooold, outdated stuff again :(

Man that s*cks! ;)

Regards
Koepi

...who is pleased anyway by the huge screen and the space on the desk and the distance to the montor.

[Doom9]

ahh.. so I gotta go looking for GFX cards with a dual link interface, as I don't plan stopping to get bigger screens in the future and I've just used up the single link DVI Interface with my 23" 1920x1200 screen.

The Apple 30" is still a bit expensive, but I'm sure there will be some serious competition not too far into the future. There already are up to 40" TFT screens, but those usually have a really low resolution.. the Apple HD display is the first one to have a size/resolution relationship that works for a display you use to work on, and not only for watching movies.

[smiller667]

I hate to say it guys, but that piece of info was #5 or so on the google results list :D ...

[Doom9]

well, why hate to say it? you've just once again made a point that everybody around here should search first and ask later ;)

[Ac3Dc3]

a size/resolution relationship that works for a display you use to work on

This is a bit OT, but right now im looking for a new screen, for movies and work, and i was thinking about a philips 23" LCD [23pf9945] - do you think that 23" @ 1280x768 is a good size/resolution relatonship ?
My other choices are 4:3 19" screens i think are too small for movie/tv viewing..

Also - what is the normal (average?) contrast ration for a CRT monitor ? that particular philips screen is only 400:1 and im a little worried about that.

Ac3Dc3.

[SeeMoreDigital]

Why have small, when you can have big: -

http://live.hitachidigitalmedia.com/http://ebizwebprod.hitachi-eu.com:83/NASApp/DMG/viewProduct_1.jsp?productid=339&drilldown=2&urlnumber=0


Cheers

[Doom9]

23" @ 1280x768 is a good size/resolution relatonship ?No, for work that resolution is way too low. 1280x768 is a good resolution for a 15" widescreen notebook display, and you could probably add two inches and still be fine.
1600x1050 would be suitable for the 19-21" range. I have a 23" Philips TFT screen with a native res of 1920x1200.. to me that's a proper resolution/size relation. You could probably go up to 25-26" with the same res but after that I'd want a higher resolution again.

Of course if you're only going to watch DVDs and have no HD plans, that's something else entirely.

And there's no 30+" screen that has a resolution suited for normal work.. those are display monitors where you have meters of distance between you and the display.. quite something else than a PC monitor.

[Ac3Dc3]

yeah, thanks, i just went to check it out in my local electronics store and got them to hook it up to a pc - it looks like 800x600 on my current screen :eek:
screen with a native res of 1920x1200
thats way too much for my needs (and budget) being in the Europe part of Region 2, where HDTV doesnt exist* and wont do untill at least 2006; so i only plan to watch dvd rips and dvd res DVB-t.

thanks for the info!
Ac3Dc3.

*Euro1080 only have very limited programming and won't really begin proper pooling of HDTV programmes untill 2006, when sky plan to start broadcasting HDTV content aswell..

[Atamido]

Originally posted by smiller667
Dual Link DVI supports 2x165 MHz (2048x1536 at 60 Hz, 1920x1080 at 85 Hz). A dual link implementation utilizes all 24 of the available pins.

Single Link DVI supports a maximum bandwidth of 165 MHz (1920x1080 at 60 Hz, 1280x1024 at 85Hz). A single link implementation utilizes 12 of the 24 available pins. Didn't anyone else find these numbers a little odd? You double the bandwidth, but the 1920x1080 res only gets a 41% increase in refresh rate? What about the bandwidth numbers?

If a single DVI connection supports a 165MHz signal over 12 wires, that means a maximum of 1,980,000,000 bits could be transfered each second. Assuming that it transfers uncompressed video at 24bit color, 1920x1080x60x24 is a required 2,985,984,000 bits of data each second, or 50% more bandwidth than the DVI connection could supply.

When you go up to Dual DVI, this would give you 3,960,000,000bits, but the same res at 85Hz would require 4,230,144,000bits. Thats closer, but not quite there.

Not that I'm questioning the authority of the DDWG, but it doesn't make sense.

[Atamido]

I don't suppose anyone has an answer to the above question?

[Soulhunter]

I thought DVI-D has 18 pins, not 12... :confused:

EDIT: Normal DVI-D -vs- DVI-D Dual Link

http://img150.exs.cx/img150/7824/1119lr.png

Bye

[SeeMoreDigital]

Originally posted by Soulhunter
I thought DVI-D has 18 pins, not 12... :confused: Agreed... this certainly would seem to be the case with all the DVI-D to HDMI connectors I've seen/used.

Anyway... if the A/V industry has its way DVI will soon become a "yesterday" method of connection :eek:


Cheers

[Tuesday]

Hey, this thread reminded me of an article i found on THG some time ago,

here:

http://graphics.tomshardware.com/graphic/20041129/index.html

specifically this page:

http://graphics.tomshardware.com/graphic/20041129/tft_connection-06.html

enjoy

[Latexxx]

Engadget had a great link today: http://www.synapps.de/synapps/bin/view/Main/CinemaDisplayWindows

[auenf]

hmm, think ill just stick with my 24" for the while, got no need for more than 1920x1200 atm

Enf...