Reduce energy usage of secondary GPU/PCIe devices

One of my Qubes installs is on 24/7 (host a few services in it) and has a secondary GPU for gaming.

Lm-sensors shows an idle energy usage of at least 10W (more if I attached it once to a VM)

This has been bothering me for a while now. I know that there a some UEFI options for pcie sleep but I couldn’t see any effect at all.

Any advice ?