Solved! Assistance request with Windows/receiver/5.1

[alientude]

I have the following devices:

Yamaha RXC-V383 receiver
Acer Predator XB271HU monitor

Homemade computer with:
EVGA GeForce RTX 2080 XC GAMING video card
ASRock Fatal1ty Gaming Z170 Gaming K4 motherboard

I'm trying to get this setup so my PC is both GSYNC enabled (requires DisplayPort) and 5.1 audio. Also, I want to route my PS4 and Nintendo Switch through the receiver to the Acer monitor.

My first thought was DisplayPort from PC's video card to monitor, and optical audio from PC's motherboard to receiver. That failed to produce 5.1 sound from the PC, however - Windows does not let me configure the speaker setup to 5.1 (the configure button is grayed out).

I've got it working using:

PC -> Monitor using DisplayPort
PC -> Receiver using HDMI

This is a little wonky (Windows sees an extra display that isn't there, but that's corrected by mirroring the screen instead of extending), but it works and gets me the 5.1 audio I want. The problem is I can't connect the monitor to the receiver via HDMI - when I do, Windows no longer sees the receiver as a sound destination - it just sees the terrible speakers on the monitor. The RXC-V383 is no longer a playback option in the Sound Control Panel.

I don't know how to get around this problem. It's not a terrible inconvenience, as the receiver sits near me, so plugging in the HDMI cable when I want to use a different input that my PC is not a big deal, but it's annoying that I have to do it, and I'd like to figure out a way to get it working without futzing with cables. Anybody have any advice? Thanks!

 

[helpstar]

The first thing you did should work. Diplayport + optical cable

You will have to select the optical digital from the onboard sound as default audio device
https://www.maketecheasier.com/use-the-optical-s-pdif-port-windows10/

 

[alientude]

The first thing you did should work. Diplayport + optical cable

You will have to select the optical digital from the onboard sound as default audio device
https://www.maketecheasier.com/use-the-optical-s-pdif-port-windows10/

I did that and can get sound, but it's 2 channel sound, not 5.1. Windows won't let me configure the output to 5.1, as the "configure" button on the Realtek Digital Output option is greyed out. I went into the properties of the device and ensured DTS Interactive is selected as the default format, but no joy.

 

[helpstar]

some suggestions from others:
https://www.techpowerup.com/forums/threads/need-help-with-5-1-surround-sound-with-w10-sp-dif.246584/

 

[alientude]

It seems like I've got this working by simply switching back to the SPDIF jack after having it all setup using HDMI. It's outputting 5.1 sound using that connection now. The only thing I can think of is that the Realtek driver is now configured for 5.1, whereas it was all grayed out before I did it using HDMI. I'm rather skeptical that this is a lasting fix, but guess I'll see.

Thanks for the suggestions.