Not Physx but ATI + Nvidia + CUDA

[Derfnofred]

Alright folks (dons stupidity suit) I asked this over in the home theater and the crickets were chirping a bit too loudly. I'm hoping you can help over here.

Not at all related to Physx, but totally cuda+ATI-related

Here's the scoop. I'm a audio nut, and one of the really cool things to come out of the CUDA world is a generic FIR audio DSP crossover setup that can compute a large number of taps very quickly and efficiently. Like this. Totally ideal stuff for stream processors (ergo, something a 9600 gso/384 would eat up, considering the software was originally written for a 9500 gt). Second part of the problem is the need for HDMI 1.3a specification to get 8 channel lpcm, so I can output said channels to my receiver.

Intelligently, I should just get a 240 gt right now, which is weaker at stream processing than the 9600 gso/384, but solves all the problems in one fell swoop. Pipe sound through it, send it down to the receiver and be done. It's just the 240 gt kinda sucks for... umm.. the money. That said, I have a sound card I prematurely bought, that I wouldn't need for this project, and sending it back/selling it gives me ~$80 more to work with. HDMI 1.3 enabled sound cards are expensive from what I've seen and the sound card won't be getting any traditional use.

The ATI 4XXX series cards (and later) support HDMI 1.3 specifications though, so I have 3 options as I see:

Keep present soundcard and buy used GTX 260/216 for video and non-game audio processing. Switch to headphones for gaming and have the soundcard/cpu take care of business. Use soundcard as a glorified DAC and pipe analog signals into receiver for playback. DACs in the soundcard might be better than a receiver, but there's the pain of piping a ton of cables around.

2&3 involve selling sound card

Buy used 9600 GSO/384 to do CUDA calculations then pipe audio data over to a used 4870 for hdmi packaging and output. And of course use the 4870 for all the video goodness. Will things blow up drivers/software doing this? 5770 would be even better, since it offers a lot more sound integration and graphical goodness.

Third option is this: gtx 260 216 core + g210 (cheapest way I've found to get the lpcm 8 signal out). Benefit is a lot more horsepower for audio processing (and double precision), but then the sound processor is intrinsically tied to graphic needs. Ergo--sound will suck during games (down about 32x the stream processing), or just use motherboard integrated sound to headphones.

Any ideas? I'm on a mATX board (p55 ud2), so I'm not made of slots. A decent graphics processor is nice, but I don't game THAT much.

Thanks...

 

[Thor]

so if i get what your saying, your using (err.. looking to use) a software dsp to process audio and pass it out hdmi. using a vid card with more power affords better sound. at a hit to gaming performance. i assume the audio out still works regardless of the software dsp. what im getting at is, would it be any easier to simply shut off the higher quality software to regain your video performance? In my experience, windows doesn't much care for having more than one sound card enabled at a time.

 

[Derfnofred]

Thor

Thanks for the question--probably helps a bit to explain:

Processing chain will work something like this:

1.) Input sound stream(anything, I hope) picked up as the pcm stream by portaudio/jack. Whether that's from a player (winamp, foobar, powerDVD, WMP, etc) or from any other source (browser, game).

2.) Sound stream piped to the CUDA-based DSP software, where the graphics card's stream processors are used to execute the rather large FIR filter. This filter will both compensate for room effects and split the signal to the individual drivers (stereo 3-way), sending 6 pcm streams back to portaudio/jack. Double precision CUDA cards should theoretically let me output a 24/96K stream as opposed to a 16/44.1K stream.

3.) Pipe said processed streams to an HDMI 1.3a enabled device of sorts for transport to the receiver.

To your question: yeah, I could shut down the audio software during video-intensive times (games) and just play from my headphones. Probably have to do that anyhow, in the case of not having access to the sound stream coming out of the game.

My bigger problem is whether a nVidia card would have a conniption fit running cuda operations on a system where an ATI video card is also aboard.

I'm probably being too ambitious, but that's part of the fun ;-)