MacOS (like other unix-based systems) by default records last access time for every file. I.e. every time you read a file, a write is made on the filesystem to record this action. There is no point in doing it and no side effects if you disable that by mounting the root filesystem with noatime flag set.
Restart the machine.
You can verify that it worked by executing the following in Terminal:
mount | grep ” / ”
You should get the following output (i.e. see noatime in the list in parentheses):
/dev/disk0s2 on / (hfs, local, journaled, noatime)