nforce2 and Dolby Digital

[Cotita]

when I saw the asus A7N8x and Chaintech nforce2 reviews I was puzzled by the fact that neither supports dolby digital output but both support 5.1 channels audio.

I was somewhat dissapointed by the lack of dolby digital out, but then I thought... What do I want it for? The only reason would be for playing games with dolby digital sound. Only doom3 will support dolby digital sound in the near future, but since it will also support EAX2.0 and DS3D, then I see no reason for it.

It seems that in the end, dolby digital encoding is more a marketing gimmick than a real feature.

[Harnagel]

From Anandtech
The nForce2 chipset debuts with two MCP offerings: MCP and MCP-T. The basic MCP is a bare MCP that is pin-compatible with the original MCP that was introduced with nForce. This MCP supports USB 2.0, ATA/133 and it has NVIDIA’s own Ethernet MAC. The basic MCP does not have NVIDIA’s Audio Processing Unit (APU) and just basic AC’97 audio support without an integrated DSP. This is the cost effective MCP that can be used on entry-level motherboard designs.

The MCP-T is the more interesting of the two as it builds upon the MCP features by adding IEEE-1394a (Firewire) support, NVIDIA’s APU (unchanged from the original nForce) and a second Ethernet MAC. This second MAC is provided by 3Com, and the combination of the two solutions allows the MCP-T to have “router on a chip” functionality. With two integrated Ethernet MACs, all that’s necessary to enable what NVIDIA calls their DualNet architecture are two relatively cheap Ethernet PHYs to bring two 10/100 Ethernet ports to a nForce2 motherboard. The most obvious configuration is where a broadband Internet connection comes into one of the Ethernet ports with the remaining port on your nForce2 system going out to a switch to provide Internet access to all of the PCs on your network. With Intel’s vision of powerful home PCs acting as content servers to the rest of the house, NVIDIA’s “router on a chip” idea seems to be validated.

http://www.anandtech.com/showdoc.html?i=1654&p=5

The Asus A7N8X uses the MCP while the Asus A7N8X-Deluxe uses the MCP-T. I'm assuming the Chaintech uses the regular MCP as well. If you want DD5.1 then you should look for a motherboard with the MCP-T southbridge.

[Harnagel]

Originally posted by Cotita
It seems that in the end, dolby digital encoding is more a marketing gimmick than a real feature.

I have never actually used this feature. I wish there was a motherboard that had an onboard decoder so we didn't need to have an external decoder. I think that would make the whole thing more practical. That way we could have the option of going through the decoder to analog outputs, or bypassing the decoder and going straight to an optical/SPDIF output.

[Cotita]

actually the asus and chaintech mobos (and some others) use the MCP-T they just don't have the digital/optical output.

It seems nvidia is not able to supply MCP in quantity and motherboard makers are using MCP-T instead.



I really see no reason to have hardware dolby digital decoding, PowerDVD and WinDVD are capable of decoding dolby digital and DTS in software and the result is every bit as good as an external decoder.

[Harnagel]

I'm assuming it takes up quite a bit of your resources to decode in software. I guess I'm just of the mindset that if you can do something in hardware and leave your CPU to do other stuff, that is a good thing.

[Prime]

The stupid Chaintech board doesn't even use the APU in the MCP-T. They have a C-Media chip onboard that handles audio output. That was the deciding factor for me NOT buying that board. My new ASUS A7N8X Deluxe should be here today.

[Matthyahuw]

Originally posted by Prime
ASUS A7N8X Deluxe This is looking like your best bet, that and the Abit...Abit's v2 is supposed to have some more overclocking options, I'm gonna wait and see! :D

[Cotita]

Originally posted by Harnagel
I'm assuming it takes up quite a bit of your resources to decode in software. I guess I'm just of the mindset that if you can do something in hardware and leave your CPU to do other stuff, that is a good thing.

For watching DVDs? hardly worth the effort.

[Cotita]

Originally posted by Prime
The stupid Chaintech board doesn't even use the APU in the MCP-T. They have a C-Media chip onboard that handles audio output. That was the deciding factor for me NOT buying that board. My new ASUS A7N8X Deluxe should be here today.

The audio is still handled by the APU, the only thing that is disabled is the digital output.

I've seen that the asus, chaintech and Abit boards can overclock to 200mhz fsb effortlessly. No VIA motherboard is able to match that without major tweaking.

Santa, can I have a nforce2 mobo and 2x512mb of pc3500 DDR for christmas? Damn, I knew I shoudn't have been a naughty boy this year.

[navek]

I find it amusing that many people here see the Dolby Digital encoding as superfluous. It is obvious that persons deriding these features are not audiophiles, and I am inclined to say that they know very little about audio hardware. Speakers that people buy for their PCs are extremely poor performers when compared with speakers that one would purchase for a mid-range home entertainment system. The Digital Analog Converters(DACs) that you would find on a gaming sound card are inferior to the ones found in low-end surround receivers. When noise is added to the mix by poorly shielded analog components inside a PC, you end up with pretty crappy sound. The digital output on my nForce2 board is nothing short of spectacular when connected to my Onkyo receiver, and it also makes it possible for me to use my Sennheiser headphones which are not adequately powered by a SoundBlaster Audigy. I just wanted to point out that there is absolutely no validity to the assertion that there is nothing to be gained from the digital outputs on the nForce2 boards. However, I will admit that many gamers are not critical listeners and/or they do not have the money to purchase quality audio components. Anyone with a surround receiver and some nice speakers or headphones will really appreciate the Dolby Digital encoding.

[Cotita]

You are right, sort of.

The optical output is a big plus if you have a dolby digital reciever since its much better than the analog output of the onboard nforce audio.

The thing is that not many gamers are willing to spend lots of money for a dedicated home theather for their pc. So even if the nforce does have a digital output, most probably it will go unused.

On the other hand, many gamers, myself included, are willing to spend a couple of hundred bucks for decent 5.1 speakers with no external decoder, like the ones of logitech, creative, altec lansing and the like.

One thing is for sure, the nforce2 audio implemetation is much better than the original nforce because the nforce analog audio was somewhat crappy and the drivers didn't support 5.1 audio.

[navek]

I definitely wouldn't go with any "digital" speakers. The DAC on the nForce2 board is probably much higher quality than any you would find in a set of PC speakers.

[Neova]

You folks should drop by the www.3dsoundsurge.com forums and www.nforcemb.com forums.

Both nforce 1 and 2 share the same MCP and MCP/T southbridge according to the forum users. Audio quality has been enhanced through software driver updates and not hard silicon, assuming you can get quality riser cards or digital out on the MBs.

I'm not a true audiophile (too poor) but my friend is. Digital out will give you only 2.1 channels in games unless it has been natively encoded for Dolby Digital (DVDs only AFAIK) or you can force encoding of EAX, DirectSound3D to 5.1 digital out but you are adding latency and "compressing" the soundstreams. Yes, Dolby Digital 5.1 is a compressed form of audio.

But if you have a quality speakers and a good decoder reciever, I bet the compression artifacts are well worth the overall sound experience. I only wish games came with true DTS or DTS EX sounds natively! Heres waiting on Doom3 before I upgrade. =)

[Cotita]

compressing 5.1 audio into AC3 is no easy task.

Its not clear if Doom3 will natively support dolby digital (extremely unlikely, since Doom3 is already taxes CPU a lot), or if it will output DS3D 5.1 audio into and use nforce2 MCP-T 2 to encode it into dolby digital. Since Doom3 will also support EAX2 I think gamers will use it instead of dolby digital.

Most, if not all, X-box games have dolby digital support, but the games themselves output DS3D sound that is latter encoded into AC3 streams by the nvidia MCP-T.

[anxdiety]

I'm thinking its going to be full dolby digital for doom 3 since they've recruited Trent Reznor of NIN to do the sound for the game yet again. And NIN's last release was done in full 5.1 audio and nails spent a ton on converting their studio to a 5.1 set-up.

[Namarrgon]

If Doom3 supports Dolby 5.1, it'll almost certainly be only in pre-recorded music - the game effects will be 3D, but the CPU will certainly not have the time to spare to encode it.

MCP-T (and Xbox) will do the encoding for you, in hardware. The only advantage is one digital cable to plug into the decoder, instead of 6 analog cables. UNLESS you plug it into a real home theatre - then there's a HUGE difference.

I run a single S/PDIF line and S-Video from my nForce2 board into the $5k Dolby 5.1 system in the living room next door. I use a wireless keyboard & mouse with it, and I get big-screen gfx and awesome 3D sound. There's simply no contest, if you have the setup :-)