Sorry, I need to be more specific.
I need to know:
(1) Does the HDMI signal need to be boosted somehow to run 40 ft. from the 5770 card to the Panasonic TV? Or is signal strength not an issue?
(2) Specifically which adaptor cable do I need to buy get the video/audio into the HDMI cable for simultaneous viewing?
40 feet is near the maximum possible.
We know that DVI is DIRECTLY adapted to HDMI, so I suggest you try a DVI to HDMI adapter off the built-in DVI port first.
To run your hp TV/Display at the same time, get a Mini DisplayPort to DVI or HDMI converter. If you ever expect to run three displays, you will need to have ACTIVE converters, so it may be worthwhile to buy one now.
Neither of your displays required Dual-Link adapters based on the data rate (Dual-Link means double the data conductors, to lower the overall clock rate to something manageable. It does not mean double display in any fashion.)
The HDMI adapters should all support Audio. Which version of Mac OS may determine whether the card can generate it.
Is that what you were asking? If not, ask for more!
OK, I'm asking more.
Bear with me, I obviously don't know much about this.
Currently the video signal is going from 5770 --> HP 2711x via DVI.
The audio is going Mac Pro-->external DA converters via optical digital out from the Mac Pro.
I don't want this to change. I have a high quality audio system for FCP X and Pro Tools.
For the Panasonic, you suggest DVI-->HDMI. For this to work, don't I have to buy an Active converter to combine the audio with the video? Otherwise, the audio wouldn't get to the Panasonic.....right? Isn't this the case regardless of whether I use three monitors or not? I am probably off base here.
Assuming I am right that the DVI-->HDMI converter needs to be Active to combine video/audio, where does the audio come from? Is it already avaliable at the 5770 DVI connection? Or must it be tied into the converter separately somehow?
For the HP 2711x, you suggested either MiniDP-->DVI or MiniDP--> HDMI. Does it matter which I choose? Will they be exactly equivalent video quality?
FYI, I am running OS 10.7.4.
I have found this adaptor
which converts DVI and S/PDIF to HDMI.
Is this what I need to get audio to the Panasonic?
Will I lose my audio to the 2711x whenever I use this?
Well, here is an alternative:
Connect MiniDP-->HDMI using this adaptor
Then, I would leave
This sure is simple........something must be wrong.
Will this work?
Great, here is one of the Apple-approved adapters here:
Wouldn't this be the way to go, and just leave DVI-->2711x?
It depends on who you trust to make the best signals to go the 40 feet.
My inclination was to use the DVI output, adapted (but NOT re-driven) to make an HDMI to go that distance.
The other way, you rely on the adapter-maker to generate nice strong signals in the adapter. It may work fine. It may even work better.
Now you have Options!
OK, Grant, I've got it.
Just two more things (a repeat of questions above).
(1) For the DVI-->HDMI-->Panasonic, am I correct that I will need this (or a similar) adapter to get audio to the Panasonic?
(2) Can I simultaneously get audio out of the S/PDIF (going to Panasonic) and Toslink audio out (going to my audio system for the HP 2711x?
Re 1) I think all you need is the simple mooshi adapter, no bells, no whistles. The apple article says the Mac Pro 2010 [which implies the standard 5770 or optional 5870 card] supports putting the Audio right out onto the display Interfaces, but the Mac Pro 2009 model [standard GT120 optional 4870] does not. So if you have the 5770, the Audio should come right out on the display interfaces, no stunt-box needed.
Re 2) IF you can simultaneously send the sound to two outputs, you would do so in System Preferences > Sound.
I'm not arguing with you, Grant, I just want to understand why I found so many articles that say audio won't come out of DVI, period.
The only article you have referenced (unless I missed it) is an Apple article discussing Mini DisplayPorts only:
Which Apple article are you referring to?
There is this one, which says in a backhanded way that the 2010 model [is required for] sound output through Both Interfaces of the display card (It was news to me -- I thought all you needed was the right display card):