NVME drive never goes to lower power states

[imk82]

Hi all,

I'm investigating a high temperature of my NVME drive. After some digging into the problem, it seems it never goes into lower power states and APST seems not to work.

Is this problem known / common or are there some tunables which must be set to make it work?

Thanks and best regards
Robert

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root@jupiter:~ # nvmecontrol power nvme0
Current Power State is 0
Current Workload Hint is 2


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Supported Power States
St Op     Max   Active     Idle   RL RT WL WT  Ent_Lat  Ex_Lat
 0 +     8.25W       -        -    0  0  0  0        0       0
 1 +     4.00W       -        -    1  1  1  1        0       0
 2 +     3.00W       -        -    2  2  2  2        0       0
 3 -   0.0250W       -        -    3  3  3  3     2000    3000
 4 -   0.0035W       -        -    4  4  4  4     5000   35000


[doktornotor]

I would hazard to say the this post very much sums up the "issue", and the solution is get better cooling.

[imk82]

I would hazard to say the this post very much sums up the "issue", and the solution is get better cooling.

What is sums up is, that if we do APST manually it scales up again when load comes to the disk and never down later. Which is correct. But that is exactly the sense of APST and power management, scale down when there is no load.

Currently my disk idles 99% of the time an is power state 0 all the time. What I want is to make it scale down automatically as it should. Better cooling would lower the temperates, but the problem is not solved. It burns like hell (equal to a spinning disk :-) ) all the time without any need.

So what I ask myself, how can I enable power management (APST) for NVME disks in OpnSense?

Best regards
Robert

[doktornotor]

Currently my disk idles 99% of the time

Hmmm, does not match my experience on any of the couple of boxes I did look at currently. Perhaps something that sits there routing pretty much nothing and logging nothing is a different story.

Looks like another "my CPU measurement seems too hot" type of debate. Here's a link to aid in your experiments until you reach the conclusion that APST will not replace proper cooling for your system drive.

https://www.truenas.com/community/threads/nvme-autonomous-power-state-transition-apst-not-working-in-core-works-in-scale.113947/

[imk82]

I use ramdisks for logging and /tmp. There is not.much writting on the disk. So it should not counsume engery without need. Noar due to the heat, nor from the cost side.

[imk82]

With following command the SSD stays in it's lowest power state for around 3 minutes:

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nvmecontrol power -p 4 nvme0
So maybe, it is a candidate for a cron job. Very suboptimal, but better than heating everything up without need.