Questions about HDMI output on cards

[venusiansky]

I am currently in the process of building a new system to replace my 6+ year old antique . As a personal requirement for the video card, I just ordered one that has HDMI output. I am still waiting for the new CPU/Mobos to be released, so I have a little bit of a wait until I can put this thing together. My questions are:

- Does the HDMI output work the same as connecting over DVI? In particular, is the video displayed during POST or do you still need to connect the DVI for that?

- How does the audio pass-thru on these video cards work? Will I connect a cable from the motherboard to the video card? I will be running Vista and fully understand the new audio architecture if that happens to be related, which I doubt.

Thanks

 

[ViRGE]

HDMI = DVI + Audio. HDMI connections can be mechanically converted to DVI with a proper adapter, and function exactly the same as DVI otherwise.

 

[QuixoticOne]

Originally posted by: venusiansky
I am currently in the process of building a new system to replace my 6+ year old antique . As a personal requirement for the video card, I just ordered one that has HDMI output. I am still waiting for the new CPU/Mobos to be released, so I have a little bit of a wait until I can put this thing together. My questions are:

- Does the HDMI output work the same as connecting over DVI? In particular, is the video displayed during POST or do you still need to connect the DVI for that?

- How does the audio pass-thru on these video cards work? Will I connect a cable from the motherboard to the video card? I will be running Vista and fully understand the new audio architecture if that happens to be related, which I doubt.

Thanks

It depends on your video card as to how audio works... I thought that most modern video cards with HDMI output also had *on the video card* an audio output chip that sent audio over the HDMI link to your monitor which would presumably have speaker outputs on it etc.

If you have certain kinds of digital audio output available on your motherboard or sound card, I suppose you could be required to plug those into some of the HDMI supporting GPUs that don't have their own audio chips on them if you want audio over HDMI.

You should be able to use either the HDMI port or adapter, the DVI port, or the VGA port/adapter and have the system boot up with console video going to whichever one you have actually plugged in. The more questionable case is where does the boot video go if you have MULTIPLE of those ports plugged in at once?

If your monitor / HDTV / receiver doesn't support audio over HDMI in the way that you need, I imagine you have the option to just have the audio come out over your motherboard's integrated audio chip or a PCI sound card without going through HDMI.

I think you'll need to read your card's documentation to get the exact answers for these specific questions.

 

[venusiansky]

Go it. Thanks!

I too heard about the cards having audio processing built-in, but I am not sure about the card I am getting which is the evga 9800gx2. I will be connecting it to my Onkyo receiver which supports HDMI with audio.

 

[Auric]

ATI, at least, outputs post video to both ports. Some older HDMI cards did require an audio connection but yeah, current ones generally sport their own audio controller.

However, the problem is that there is little advantage to using HDMI audio from video cards at the mo'. Only a few mobo-integrated solutions work and those require using the relatively poor integrated graphics. HDMI audio on cards can replace S/PDIF and analog for how they have always been used before recently but alas cannot replace analog for handling HD formats due to lack of anti-copy scheme.

So, the preferred connection for the time being is an audio card with high quality analog output. As for the video card, HDMI ports are not necessarily desirable as they have generally demanded a premium yet do not offer anything over DVI-I with adapter (except, perchance, in the case of aforementioned older cards that lacked an audio controller).