NVIDIA RSX to power Playstation 3 audio?

Dave at Beyond3D has pointed out some slides now online from Sony’s presentations at GDC that include some juicy details about the Playstation 3 and the chips that power it. Among the slides is a high-level block diagram of a PS3 system that shows many of the system components connected as one would expect. But right there among them is an arrow shooting out of the side of the NVIDIA-supplied RSX graphics processor with a label that will raise some eyebrows: “8 Ch. Audio”. This suggests none too subtly that the RSX will provide the PlayStation 3’s audio capabilities as well as its graphics.

I would be more inclined to dismiss this possibility outright had I not been sitting in a room with NVIDIA CEO Jen-Hsun Huang when the Playstation 3 deal was announced. That very morning, Huang said NVIDIA would create another SoundStorm, referring to the popular but ill-fated hardware-accelerated audio processor in NVIDIA’s early nForce chipsets. My account of that conversation read, in part:

Huang told the assembled press types, “We’re gonna build SoundStorm 2. It’s gonna be awesome.” He was less clear on what form the next SoundStorm would take, saying that NVIDIA was still trying to figure out how to deliver SoundStorm as a product. Huang said, cryptically, that the new SoundStorm “will come in a way that you won’t expect.”

In the same Q&A session, Huang spoke about NVIDIA’s history with the NV1 “media processor” chip, which had built-in sound as well as graphics. He disputed that notion that NVIDIA is primarily a “graphics company,” and then suggested that the GPU is going to evolve and expand beyond graphics to include other kinds of digital media.

The wording of this statement made one wonder whether NVIDIA might be providing the audio capabilities for the PS3. This slide from Sony’s GDC presentation would seem to suggest that it’s so.

Of course, we don’t know what sort of audio capabilities the RSX may include and whether they will rise above the basic AC’97 or Azalia (HD Audio) interfaces NVIDIA has already designed for its nForce chipsets. If this is the “SoundStorm 2” Huang promised, one would expect true hardware DSPs and 3D positional audio capabilities from it. One of the more tantalizing prospects, given that the audio capabilities are located on a GPU, is the possibility that RSX might use its pixel shader processors to manipulate audio streams. That’s just wild speculation on my part, though. We’ve asked NVIDIA for comment on all of these issues, but we have yet to hear back.

Beyond the apparent revelation about RSX audio, these slides also offer some insight into the RSX’s graphics capabilities. One slide lists basic specifications, and claims the RSX GPU is “NV47 based.” Beyond3D notes that NV47 was a code-name for G70, the GPU better known as the GeForce 7800. We’ve expected the RSX to be based on the GeForce 7 series graphics architecture, but this is confirmation, with additional detail. The slide says RSX will be capable of 24 texture lookups and 384 FLOPS per clock, suggesting the RSX probably has the same 24-pixel-shader configuration as the desktop G70 and G71 GPUs from NVIDIA. However, the RSX will communicate with its 256MB of dedicated memory over a 128-bit memory bus, half the width of the memory interface for the desktop G70 and G71 chips. The 22.4GB/s of bandwidth this memory config yields should be sufficient, since the PS3 will “only” have to drive HDTV-class displays.