getting my head around soundcards / headphone 7.1

[sunshinewelly]

I use my pc for gaming and movies and have a motherboard with realteck sound chip (i assume its fairly basic) - this then goes into a dennon x2200w amp and into a 7.1 speaker system

I have a gtx 1080 GPU.

Now when i use my PC for gaming or movies am i actually using the motherboards sound card as my HDMI lead is obviously plugged into the GPU.

just wondering if fitting a sound card makes any real difference to my set up.

 

[Marsman]

If you are using HDMI, then no, you're not using the Realtek onboard audio. Onboard audio only applies to the 3.5mm analogue audio input/outputs. Any digital audio output is just a transport for what is audio data.

When someone says they would like a sound card for an improvement over say onboard audio, then that only applies to the analogue connections; so speakers that are connected via analogue or headphones. The sound card or onboard audio is handling the conversion of digital audio data into an analogue audio signal, which can then be used by the connected speakers or headphones.

With digital, whether it is HDMI or optical, the conversion from digital audio data into what eventually becomes sound, is done by whatever is connected on the other end of the digital cable; so in your case, the Denon AVR.

HDMI is always preferable over optical, because it has much greater bandwidth and doesn't require compression that optical does in order for multi channel audio to be passed via it. To make use of a sound card, you'd have to connect to it directly; which would be optical. No point in doing that because HDMI is superior.

 

[EsaT]

Yep, save your moneys.

Only reason for getting sound card for use with AVR and surround speakers would be, if AVR lacks HDMI and has only optical input.
Then sound card could do Dolby Digital encoding for getting sound to AVR in digital form.
(+fixing ground loop issues)