'ssd' fstab option for HDD volume in DSM 6.2.4

Greetings,

Output from fstab is below. All listed volumes are housed on mechanical HDDs. Any idea why the 'ssd' option is present for the smaller data volume?

`none /proc proc defaults 0 0` `/dev/root / ext4 defaults 1 1` `/dev/vg1/volume_2 /volume2 btrfs auto_reclaim_space,synoacl,ssd,noatime 0 0` `/dev/vg1/volume_1 /volume1 btrfs auto_reclaim_space,synoacl,noatime 0 0`

I edited fstab, but it reverts on reboot. I'd rather make a permanent change to fstab is possible, rather than employ a startup script to band-aid this; that is, if the 'ssd' option negatively affects performance.

Can't find the answer to this particular question anywhere. Thanks in advance for the knowledge.