Question Graphics and sound cards are not working together

[broj_jedan_a]

I have:

- ASUS ROG STRIX Z790-A Gaming WIFI II LGA1700 motherboard​

- Gigabyte AORUS XTREME ICE GeForce RTX 4080 SUPER graphics card (vertically mounted using NZXT Vertical GPU Mounting Kit)​

- Sound BlasterX AE-5 Plus Pure Edition SABRE32 Ultra-Class sound card.​

When both cards are connected to the motherboard at the same time, only the sound card works.
System does not recognize the graphics card at all.

Both cards work just fine when connected individually.

In both scenarios, graphics card is installed on PCIe slot G5 (closest to the processor) and sound card on PCIe slot G4.

Any thoughts on what could be the cause of this issue?
Has anyone experienced anything similar?
How to fix this?

Any help is greatly appreciated.

 

[COLGeek]

Which is the default playback device in sound settings?

 

[Lutfij]

Welcome to the forums, newcomer!

Gigabyte AORUS XTREME ICE GeForce RTX 4080 SUPER graphics card (vertically mounted using NZXT Vertical GPU Mounting Kit)
Without the riser, do you encounter any issues? Can you drop the sound card onto slot G3? What BIOS version are you on for your motherboard?

 

[broj_jedan_a]

Which is the default playback device in sound settings?

Speakers

 

[COLGeek]

Speakers

I meant what sound device.

 

[broj_jedan_a]

Welcome to the forums, newcomer!

Gigabyte AORUS XTREME ICE GeForce RTX 4080 SUPER graphics card (vertically mounted using NZXT Vertical GPU Mounting Kit)
Without the riser, do you encounter any issues? Can you drop the sound card onto slot G3? What BIOS version are you on for your motherboard?

I haven't tried it without the riser. The graphics card can't fit in the case horizontally.
BIOS version: 0404, 28.9.2023

 

[broj_jedan_a]

I meant what sound device.

Now, without sound card, it's Realtek USB audio.
With sound card, I can't remember the exact name, but the system immediately recognizes the sound card and sets it as the default audio.

 

[COLGeek]

When both cards are connected to the motherboard at the same time, only the sound card works.
System does not recognize the graphics card at all.

It is normal for Windows to only have one default sound playback device at a time. This seems normal. If the soundcard is connected to your speakers, that seems okay.

Your GPU's audio adapter would not playback via speakers connected to the soundcard.

What am I missing here?