Wouldn't Dolby Digital 5.1 cripple one of the cores in X360?

[Guden Oden]

Yea I wonder about this too, I mean if DD 5.1 is trivial and can be hadled by a single thread why was the Xbox1 the only system capable of REALTIME DD 5.1 last gen?

It's trivial to a processor as of 2005, but not four years ago. Even so, PS2 could probably do DD5.1 on its VU0 vector unit if someone just tried. DTS5.1 is apparantly trivial, though DTS isn't as tightly compressed as DD so it's bound to be easier in any case.

Seems like a cheap ~$5 sound chip would have been a good addition. They will have to encode the audio info to a DD bitstream on the fly, that has to take some small bit of CPU to do.

Well, that 'little bit' apparantly isn't enough to warrant the $5 sound chip.

 

[SanGreal]

Seems like a cheap ~$5 sound chip would have been a good addition. They will have to encode the audio info to a DD bitstream on the fly, that has to take some small bit of CPU to do.

Sell 100 million consoles and that $5 isn't so cheap anymore.

 

[ninelven]

erased

 

[blakjedi]

It is if you raise the price $5.

 

[AlNom]

what process was the MCP-T built on? Did it shrink during the life of the Xbox?

 

[SanGreal]

It is if you raise the price $5.

In theory, but it doesn't work like that. People won't be willing to pay an extra $5 for a dedicated sound chip by itself. So yeah, you could put it in and raise the price $5, but the people who pay the extra $5 would pay it without the chip anyway. So you're still losing out on $5 you could've had per console.

 

[GwymWeepa]

Seems like a cheap ~$5 sound chip would have been a good addition. They will have to encode the audio info to a DD bitstream on the fly, that has to take some small bit of CPU to do.

An extra chip adds quite a bit of cost if you already have a beefy cpu. Let's say MS sells 20 millions 360's like they did with Xbox, well that's 100 million right there on unnecessary chips.

 

[AndrewM]

What if nvidia replaces their video encoder/decoder in RSX with their APU from nforce/xbox?

 

[wco81]

Any word on newer sound formats being supported?

Blu-Ray and HD-DVD will both support newer formats from both Dolby and DTS, one of which includes lossless codecs (forget which).

Obviously for BR movie playback on the PS3, the Cell will have to decode them.

But it might take awhile for people to upgrade to new receivers, speaker setups, etc.

 

[London Geezer]

Any word on newer sound formats being supported?

Blu-Ray and HD-DVD will both support newer formats from both Dolby and DTS, one of which includes lossless codecs (forget which).

Obviously for BR movie playback on the PS3, the Cell will have to decode them.

But it might take awhile for people to upgrade to new receivers, speaker setups, etc.

People will be tired of upgrading just for consoles. The next big upgrade will be HDTV.
"Normal" DD or DTS will be around for years to come, and for the time being are more than good enough. Not everyone has DD/DTS systems anyway, switching already when the old format is not very widespread is not a good idea.
DD/DTS 5.1/6.1/7.1 in every game and HDmovies will be enough for a long time without the need for new incompatible formats.

 

[Shifty Geezer]

Besides, if the audio's done on the CPU they can add any sound system they want.

 

[AlNom]

A3D2.0 8)

 

[west]

Southbridge chip which deals with a variety of functions like audio

link
thread over

 

[pc999]

If I remember right, in the TeamXbox Interviwe they sayed that they had put some special intructions for audio in the CPU.

 

[Shifty Geezer]

I don't trust that Gamespy article. I remember too MS officials saying the CPU was so fast there's no need for a dedicated audio processor. Plus if you look at the information preceding that above statement...

The CPU and GPU are linked together by a blisteringly fast data bus which can transfer operations at an incredible 5.4 Gb per second. Couple this together with the TV encoder chip (responsible for the various high-definition output modes that connect to HD-compatible displays) and the Southbridge chip which deals with a variety of functions like audio,

1 - Since when did the CPU and GPU communicate at 5.4 GB/s?
2 - Since when was 5.4 GB/s 'incredible'?

 

[Teasy]

There's one obvious reason for MS not including a sound chip. Its better PR to spend that money on the CPU and use that for sound (even if its not quite as cost effective). Which system sounds more powerful?

1: - Dual core 3.2Ghz CPU and a DD 5.1 Sound chip
2: - Triple core 3.2Ghz CPU and no sound chip

The first system may very well be as powerful as the second in any next gen game and slightly cheaper. But the second option looks far more powerful to the general public. Because most people ignore the processing power neccesary for high quality sound.

Also the second option is more flexible as you have more general purpose processing power. Though to be honest I can't see any next gen game not using DD5.1 so I doubt that flexibility will be very useful.

 

[SanGreal]

http://www.extremetech.com/article2/0,1697,1817026,00.asp

ET: The original Xbox had an audio DSP in the Xbox MCP chip. Is there a DSP in the Xbox 360?

TH: The audio is handled on the CPU cores. Part of the flexibility of the whole system is that you can have these three cores and six different threads, so you can choose to do a lot of audio there, or if you have a game where you don't have a lot of audio you can do other stuff. We want to continue to give developers the tools to realize their vision of high-definition games.

ET: So the SiS I/O chip contains the digital to analog conversion, but all audio processing is host-based?

TH: Yeah, the DAC is in the south bridge.

 

[3roxor]

Because most people ignore the processing power neccesary for high quality sound.

and aprox how big is that? 1/2 of 1 of those cpu's

 

[Teasy]

I'm not sure how much processing power it takes, so someone else will have to answer that. I'm just going by the thread titles suggestion that DD5.1 would take a whole core to process. But either way its a decent amount of power.

My point really was just that the general public tend to ignore sound chips when judging how powerful a system is. They look at the CPU speed and how many cores it has and the GPU speed and how many pipes and its bandwidth ect and amount of system ram. Sound chips don't get a look in.

 

[SanGreal]

Here is another comment on it:

The first Xbox had the nVIDIA’s MCPX (Southbridge) housing an APU dedicated to audio processing. How is the audio processed in the Xbox 360?

Todd Holmdahl: Xbox 360 has hardware accelerated audio decompression for Windows Media audio content. This allows game audio assets to be greatly compressed on both disk and in memory while delivering world-class audio fidelity. The other audio features are done on the multi-core CPU hardware.

Having an Audio Processing Unit alleviates the CPU from handling the audio. Wouldn’t it have been better for the Xbox 360 to have a dedicated audio chip, like the first Xbox, to handle the audio processing instead of the CPUs doing that work?

Todd Holmdahl: Actually, no. Doing the audio on the CPU allows the game developer to dynamically allocate hardware resources between their desired functions. We chose to use general purpose audio processing for the Xbox360 to maximize overall performance and minimize silicon overhead. The one exception to this is the audio codec, which has specialized hardware support.

http://interviews.teamxbox.com/xbox/1190/Xbox-360-Interview-Todd-Holmdahl/p1/