# Audio output of MSI 660 Ti PE?



## Frag_Maniac (Sep 27, 2012)

I'm considering getting this card soon, which has HDMI. I've read Nvidia based cards with HDMI have their own HD audio codec which can pass HD audio to your receiver. I want details though. Can it encode and pass through the 5.1 Dolby Digital that games use, or does it just pass a 2.1 PCM signal? Here I've been thinking my Yamaha receiver may have been at fault for me getting only PCM 2.1 or Pro Logic II options in games that support Dolby Digital, but it appears to be something else.

I am currently using a fiber optical cable in a pass through from my ASUS P6X58D-E MB. However in the advanced audio properties for Realtek Optical out I only see 2 channel options. Via Googling I found a thread on EggXpert that says ASUS MBs with Realtek HD ALC889 codecs aren't in fact licensed for such surround encoding. If that is true, screw ASUS, I'm done with them. http://www.eggxpert.com/forums/thread/759896.aspx

Enter the MSI 660 Ti Power Edition. Does it's HDMI audio codec encode Dolby Digital 5.1 in games? I've read ATI cards with HDMI dating back at least to the 4000 series do allow 5.1 and even 7.1 settings in the optical output panel. God forbid I should feel compelled to switch back to ATI should Nvidia's HDMI cards not though, and if it depends on the sub vendor (ASUS, Giga, MSI, etc) all the more confusing.


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## Jstn7477 (Sep 27, 2012)

ftp://download.nvidia.com/XFree86/g...-hdmi-audio.html#_types_of_hdmi_audio_support

I'm fairly sure that the HDMI audio works nearly the same on NVIDIA cards as AMD's implementation. Both have robust integrated solutions for digital audio.


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## Frag_Maniac (Sep 27, 2012)

Not sure I buy that. Nowhere in that link you provided are the words Dolby or encode mentioned. For an audio codec to pass through 6 discrete 5.1 channels, it has to first be recognized by the chip before being passed through.

Furthermore I just called EVGA's pre sales tech dept, and their guy says non of their cards encode DD 5.1 via HDMI. Obviously all of their's are Nvidia based. Another thing that makes me skeptical about whether Nvidia is even interested at all in encoding DD 5.1 via their built-in HD audio chip is they some time ago after MS dropped HAL support started backing their own Nvidia PureVideo decoder, which claims, claims mind you, to support 5.1 audio. Many have said it does not in fact work for surround sound as they claim.

This chart however, claims Nvidia GPUs dating back even to the 200 series support Dolby Digital via HDMI. From what the EVGA guy was saying it's different with games though because the compressed signal games use is PCM and has to be encoded first. So if you say had a DD source on your HDD or streamed from the net, then the GPU's HDMI would output it, but not if it's carried via PCM. Oddly enough, console system hardware have chips with firmware such as Dolby Digital LIVE that encodes DD 5.1. It seems most PC hardware doesn't.

http://nvidia.custhelp.com/app/answers/detail/a_id/2796

I'm going to do some more research on this, and if I find no one has a video card that encodes 5.1 via HDMI, I will have to get an inexpensive sound card that supports Dolby Digital LIVE and put up with an inferior coaxial or optical audio cable.


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