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[Z390-F Gaming] "Above 4G decoding" kills wake up from sleep

Level 7
Hi folks,

This post is a conclusion of a loooong search for the culprit why my Windows 10 system will not resume from sleep mode successfully .
In short; the system would go to sleep and "turn on" when tried to be woken up but never got to a working state. Fans, RGB lighting, etc. etc. all turn on but basically the system just hangs/is frozen. In every other sense the system is stable as a rock! I never ever experience issues with stability.

I've been through all the usual suspects regarding these kind of issues like Windows itself, iffy drivers, BIOS versions. I even found some references that a 2080 Ti could have compatibility issues with the Samsung 970 NVME drives. All of those trails did not end up solving the problem. As it turned out it was one little ostensibly innocent option in the BIOS called "Above 4G decoding". Given the fact I've got Asus ROG-STRIX-RTX2080TI-O11G-GAMING with 11 GB of video RAM enabling above 4 decoding seemed like a plausible setting to enable (although to this point I am not sure what it does EXACTLY).

When this option is enabled the system just will not wake up successfully. When it's disabled; no problem!

So this boils down to a few points/questions (in order of relevance):
- If you're pulling your hair out and can't find the cause of the same issue; try this! I hope it will save you time and frustration.
- How does disabling the above 4G decoding affect my system? (I am in no way a miner or something. Just gaming)
- Are other people having this issue?
- What could cause this behaviour?
- Should Asus be made aware of this, and if so; How?

aussiekendoll wrote:
you have to enable SR-IOV under PCI subsystem if you turn on 4g-degode to get rid of this problem!

No that is not required as that is for Video card virtualization.

Super Moderator
I haven't seen this behavior before simply by toggling this. Could be linked to overclocking instability, as you haven't outlined anything regarding this in your post.
13900KS / 8200MT CAS36 / ROG APEX Z790 / ROG TUF RTX 4090