NVME powersaving script
07-05-2020, 11:15 AM
I've been doing some testing and I think I can confirm that this functions the way that I thought. I can not find a way to check what the actual power state that the NVME is using, so I realize that my testing might not be exact, but here's what I found.
First of all, I'm using a PBP with a 64gb MMC and a 1tb Intel 660p NVME drive. The OS is on the MMC and my home folder is on the NMVE.
I first ran the script "nvmelowpower.sh" that contains "sudo nvme set-feature /dev/nvme0 -f 2 -v 2." I then viewed the "Energy Consumption Statistics" included with KDE while on battery power. The "Consumption" reads between 3.70 W and 4.2 W.
Then I opened up gnome-disks and ran a large benchmark on the NVME drive. The consumption then hovered between 4.5 and 5.2 W.
Next I ran the script "nvmehighpower.sh" that contains "sudo nvme set-feature /dev/nvme0 -f 2 -v 0." I let the system set for a few minutes to give the NVME APST a change to kick in. Consumption returned to between 3.7 and 4.2 This confirms that the NVME is utilizing APST to enter power savings mode even when the power management is set to 0 (the highest power). I was concerned about this for some time because I couldn't figure out how to check current power state of NVME drive.
Next I opened up gnome-disks again and ran the same large benchmark while watching the "Energy Consumption Statistics." The consumption jumped to between 7.2 W and 8 W! After the test I let the system sit for a few minutes just to confirm that the drive would return to its power saving state, which it did (between 3.7 and 4.2).
So, I believe this confirms that these scripts are working as intended to allow for throttling while on battery power. If I am ever in need of a fast read or write I can always run the script "nvmehighpower.sh" but most of the time that I would need such a thing I would be on AC anyways. This makes a savings of around 2-3 W according to the Energy Consumption monitor included with KDE. Now, it does make the drive slower by a not insignificant margin, but it is by no means unusable. Actually the benchmark with the nvmelowpower.sh script is similar to the EMMC (120 MB/s read speed). While the nvmehighpower.sh script offers very fast performance (1 GB/s read speed). I didn't test write speed because I don't feel like adding that much wear just to see if it's working.
FWIW, I ran a test with "sudo nvme set-feature /dev/nvme0 -f 2 -v 1" and found that the power consumption was very close to the 2 setting, but the read speed was around 700 MB/s. Since this represents the best compromise for my drive, I think this is what I'm going to stick with on battery power.
I hope this helps! Thanks to everyone on the Pinebook Pro team for offering such an awesome device. I love mine!
-Josh
First of all, I'm using a PBP with a 64gb MMC and a 1tb Intel 660p NVME drive. The OS is on the MMC and my home folder is on the NMVE.
I first ran the script "nvmelowpower.sh" that contains "sudo nvme set-feature /dev/nvme0 -f 2 -v 2." I then viewed the "Energy Consumption Statistics" included with KDE while on battery power. The "Consumption" reads between 3.70 W and 4.2 W.
Then I opened up gnome-disks and ran a large benchmark on the NVME drive. The consumption then hovered between 4.5 and 5.2 W.
Next I ran the script "nvmehighpower.sh" that contains "sudo nvme set-feature /dev/nvme0 -f 2 -v 0." I let the system set for a few minutes to give the NVME APST a change to kick in. Consumption returned to between 3.7 and 4.2 This confirms that the NVME is utilizing APST to enter power savings mode even when the power management is set to 0 (the highest power). I was concerned about this for some time because I couldn't figure out how to check current power state of NVME drive.
Next I opened up gnome-disks again and ran the same large benchmark while watching the "Energy Consumption Statistics." The consumption jumped to between 7.2 W and 8 W! After the test I let the system sit for a few minutes just to confirm that the drive would return to its power saving state, which it did (between 3.7 and 4.2).
So, I believe this confirms that these scripts are working as intended to allow for throttling while on battery power. If I am ever in need of a fast read or write I can always run the script "nvmehighpower.sh" but most of the time that I would need such a thing I would be on AC anyways. This makes a savings of around 2-3 W according to the Energy Consumption monitor included with KDE. Now, it does make the drive slower by a not insignificant margin, but it is by no means unusable. Actually the benchmark with the nvmelowpower.sh script is similar to the EMMC (120 MB/s read speed). While the nvmehighpower.sh script offers very fast performance (1 GB/s read speed). I didn't test write speed because I don't feel like adding that much wear just to see if it's working.
FWIW, I ran a test with "sudo nvme set-feature /dev/nvme0 -f 2 -v 1" and found that the power consumption was very close to the 2 setting, but the read speed was around 700 MB/s. Since this represents the best compromise for my drive, I think this is what I'm going to stick with on battery power.
I hope this helps! Thanks to everyone on the Pinebook Pro team for offering such an awesome device. I love mine!
-Josh