nVidia, HDMI, and 5.1 audio

[QuietIce]

I'm looking to buy a video card for my HTPC and I've found ATi cards with on-board sound but not nVidia. On-board sound isn't a requirement, the motherboard's on-sound I have isn't too bad so I could tie that in using an internal connection - if there is one. I'd rather use nVidia than ATi because I can Crunch on it using CUDA when I'm not watching The Tube.

Unfortunately, my TV is rather stubborn about what it will accept for HDMI. From what I've read (on Samsung's site) a DVI/HDMI converter is not an option here. Don't ask me how that is different from "pure" HDMI, I don't know :shrug: (If you know please enlgihten me! ;)) Not being a big gamer I'm "video stupid" so other than the resolution I need to use I'm pretty much at a loss here.

Any suggestions for an nVidia card that will import HD sound from the motherboard, which does have a 2-wire connector for that, or has on-board sound and has HDMI output ...???

[nd4spdbh2]

most of the GTX series have a spdif header. if you pair that with a sound card that does dolby digital live or DTS connect you can encode in real time a 5.1 stream.

Also i dunno what your tv manual is saying but there should be no reason as to why your tv wont accept a dvi to hdmi 1920x1080@60hz@32bit source.

Hell take a look at this

http://www.newegg.com/Product/Product.aspx?Item=N82E16814187070

comes with a HDMI port already on it and a spdif cable to go to your sound card.

[glorp]

The best thing to do is to make sure what sound sources you want to transmit through the gfx card before you buy anything. As was pointed out, the NVIDIA 2xx (and most 9xxx) cards have SPDIF connectors on them so you can connect that to your mobo if it has one. The trouble is that SPDIF will only handle:
up to 640k AC3 5.1
up to 1536k DTS 5.1
2-channel uncompressed PCM

But it won't handle:
multichannel uncompressed PCM (what will be in many games)
any HD Audio formats like DTS-HD, Dolby-HD, etc. (the HD audio stuff that's on Blu-Ray)

and as nd4spdbh2 says, if you want to create DTS from uncompressed multichannel PCM you can get a sound card that handles the recompression on the fly to DTS (called DTS-Live). Most mobo sound drivers don't do that for you that these days. ATi cards can do uncompressed multichannel PCM so you can weigh that issue with the potential need for an extra sound card with NVIDIA. ATi cards still really don't do HD audio though. You need an ASUS Xonar for that.

Remember, whatever formats you transmit your TV has to be able to decode them if that's all you're hooked to. Most only handle 5.1 AC3 or 2.0 PCM.

[nd4spdbh2]

its ambiguous.... hdmi only has a 1 wire for a digital audio connection and 1 wire for the shielding of it.

The connection on the nvidia gfx cards is just an extension of that so you can connect up a digital audio source to your card to transmit through the HDMI cable.

Like stated tho if you connect up to a sound card that only does SPDIF pass through your gonna get 2ch audio unless the source being played has an already encoded surround stream. Now if you hook up that lil spdif header on the nvidia card to a sound card that does DDL or DTS connect ull get your surround sound from games n whatnot.

BUT IMO, it would just be better to go straight from the sound card to a receiver in that case.

[QuietIce]

The best thing to do is to make sure what sound sources you want to transmit through the gfx card before you buy anything. As was pointed out, the NVIDIA 2xx (and most 9xxx) cards have SPDIF connectors on them so you can connect that to your mobo if it has one. The trouble is that SPDIF will only handle:
up to 640k AC3 5.1
up to 1536k DTS 5.1
2-channel uncompressed PCM

But it won't handle:
multichannel uncompressed PCM (what will be in many games)
any HD Audio formats like DTS-HD, Dolby-HD, etc. (the HD audio stuff that's on Blu-Ray)

and as nd4spdbh2 says, if you want to create DTS from uncompressed multichannel PCM you can get a sound card that handles the recompression on the fly to DTS (called DTS-Live). Most mobo sound drivers don't do that for you that these days. ATi cards can do uncompressed multichannel PCM so you can weigh that issue with the potential need for an extra sound card with NVIDIA. ATi cards still really don't do HD audio though. You need an ASUS Xonar for that.

Remember, whatever formats you transmit your TV has to be able to decode them if that's all you're hooked to. Most only handle 5.1 AC3 or 2.0 PCM. !!!!! And there's the answer !!!!!

While I've had lots of experience with home theater components I've never brought it down to the PC level before now so I'd never thought about incompatible sound formats. :bang head: Those comments brought me back to something I'd read in the Samsung manual about only using 48 kHz sound on HDMI, which lead me to wonder about using the Azalia HD Audio setting in BIOS. I went in and turned off HD audio but left Azalia NB audio on and everything is fine - sound though the on-board HDMI! :santa: I think that's the only thing I didn't try since I ass-umed HD sound would be standard for HDMI.


glorp, thank you very much for explaining this to a PC A/V n00b ... :):thup: