Question Sleep/Wake issue for x570 and Asus Hyper M.2 nVME expansion card & root cause


Senior member
Aug 17, 2002
I've been struggling with a wake instability issue for the last several months........ Intermittently wake would cause the fans to spin up (including HDD's) but no display or any further progress from this point requiring a reset. Frustrating as my setup used to be fully stable in this scenario and some change lead to the instability (new driver, new BIOS, .....?). Sadly not much help with a Google search as this seems to be a very common symptom with many possible solutions.

To make it difficult to diagnose, no crash dump was written and the only hint was a "/device/raidport2 reset" message to the event log (this only happened occasionally).

I'd previously ruled out the "Asus Hyper M.2 expansion card" as the culprit as pulling this card out did not solve the wake instability issue! Instead I went down a rabbit hole of installing earlier BIOS and chipset drivers etc that I would have used when this was all working correctly in the past - leading to a impasse of resolving the problem (for some time - I had to disable the use of Sleep/Wake and consume more power)

The symptoms were consistent with something resetting the PCIe bus on wake; this would take the "C" nVME drive offline during the wake. Sort of like pulling the plug out of your "C" and putting it back in during a boot; things won't work well.

I finally tracked it down to the BIOS configuration setting to set the 2nd 16 lane slot in PCIe Bifurcation mode; effectively allowing the Hyper M.2 card to divide the 16 lane port into 4 sets of 4 lane's for the nVME drives. For the x570 you typically only get 2 additional nVME drives as only 8 lanes are configured.

As soon as the 2nd 16 plane slot is configured for birfurcation, whether a card is plugged in or not, then the wake instability happens intermittently (usually a 50% chance; but I've had it run for days as well ok).

I expect that I'm probably not alone with this issue as others may have gone down this same road with the price of nVME drives falling significantly over the last couple of years. I have an Asus ROG Strix X570-E Gaming MB; which is listed as supported by the Asus Hyper M.2 Gen 2 card....... same manufacturer and presumably tested by Asus as a working combination.

You actually don't need the Hyper M.2 card..... just using the BIOS bifurcation setting (that other 3rd party nVME expansion cards need as well) makes the wake unstable. In my case, it's made the Asus M.2 card totally unusable and has been removed from my system (and changed the BIOS setting back)

Curious to see if anyone else has seen a similar issue?
And whether this is another example of recent Asus quality woes or whether there is something else I missed.