Soundscapes – The graphics card is your new sound card

It’s possible to use any AMD or Nvidia graphics card for sound, but this feature isn’t discussed at all. When I bought a new surround receiver the other week for my PC audio setup, I decided to test this feature of my graphics card. It turned out to be both better and worse than a dedicated sound card in ways that I didn’t expect.

Using a graphics card for sound comes with many limitations. Unlike a normal sound card, a graphics card can only output sound digitally via HDMI or Displayport, so it’s actually just half a sound card. In order to get sound from it you have to plug it into something which has a DAC (digital to analogue converter). This can be the built-in speakers in a monitor, or TV, or a surround receiver, which takes the digital sound data coming from the graphics card and then converts it to analogue which is sent to your speakers. A normal sound card has this DAC section built into it. The DAC section is what makes the biggest impact on sound quality. If you buy one of the higher end sound cards from Asus, for example, it’s the DAC section which is most improved over the entry level models. Every device that produces sound whether it’s an iPhone, computer, DVD/Blu Ray player etc has a DAC. If you’ve ever wondered why high end CD players even exist in the first place it’s because of the improved DAC section over cheaper models.

A monitor with built in speakers, a surround recevier or a DAC with HDMI input. You have to have either of these in order to get sound from your graphics card

For my testing I used a Geforce 580 which via HDMI connected to a Pioneer VSX-2021 surround receiver. The features available on the graphics card are as basic as it gets. You can pick the number of speakers and that’s about it. There is no mic or recording inputs of any kind. The simplicity of the drivers meant that I never at any point ran into any issues with stutters or drops of audio in all my testing when playing games, watching movies and listening to music. Ever since Windows Vista, simple generic audio devices drivers have had to live up to a basic level of stability that makes the audio experience rock-solid no matter what. Thanks to the surround receiver I was using I could still do some processing to the audio signal, such as down mixing 5.1/7.1 to stereo, or in my case 4.2 which is the setup I’m using now. 4.2 is two speakers in front, two as surround speakers and then two subwoofers. The operating system and all the applications I ran believed I was using 5.1 while the receiver down mixed the signal to the actual number of speakers I had. This feature isn’t unique, as every surround receiver I have come across in the past 10 years has had this feature. It’s only in more recent years that this has become a feature you might want to have while playing PC titles, as some games don’t down mix 5.1 to stereo in the way they should.

There are several limitations with using a graphics card for sound apart from the lack of recording inputs. You can’t, for example, plug a HDMI cable to a receiver and expect it to only receive audio. You have to use it as a video switcher as well, so sound and video must travel via the receiver before going to the monitor. Given that there are no surround receivers with Displayport input yet, it means you are limited to 1080P displays at 60hz. So if you’ve got a 120hz 3D monitor or a display with 2560*1440 resolution or more, this won’t work since HDMI doesn’t have enough bandwidth. Another minor issue I ran into was that the graphics card thought the monitor had been unplugged every time I switched off the surround receiver. This meant all the windows open on the desktop were resized to 800*600 resolution. I leave my machine on all the time, so it was annoying to have to resize all the browsers, for example, to the size I wanted.

There has to be a display on the other end of the signal to use a graphics card for sound output. Plugging it into a receiver without any display on the other end will not work at all.

For all the limitations that come with using a graphics card for sound it still has its uses, although they might be niche. If your monitor has built-in speakers but you generally listen with headphones, you could still use the built in monitor speakers for casual use such as youtube or podcasts when you don’t feel like putting on the headphones. If you’re looking at seriously improving your computer sound setup with a surround receiver, or maybe just putting a HTPC in the living room, using the graphics card for audio works great. Note that my experience only reflects using a Nvidia card so things might be different with AMD, but I see no reason why they should be. This feature will only ever serve a tiny group of users, but don’t forget that it’s there if you’re ever in the situation where it might be useful.