Does anyone understand Audio Acoustic Management?

[jrichrds]

The AAM (Audio Acoustic Managmenet) standard on Hard Drives...anyone understand how it works?

It can be adjusted in 126 different steps (IBM's AAM util labels them as 128 to 254, but they're actually hexadecimal values).
They seem to be categorized into 3 different "levels":
128-192 = Low Acoustic Emanation level (quietest seek)
192-253 = Medium Acoustic Emanation level (balance between noise and performance)
254 = Maximum Performance

My questions are:
1. Are all steps within each levels the same? Or can drives really be tweaked with 126 different noise levels?

2. Is the final step (Maximum Performance level) the same as having AAM disabled?

 

[Lord Evermore]

I don't know all the answers, but the way it works is essentially slowing down the positioning arms when they seek, so they're not "snapping" to position quite as much. There is probably another feature to it as well, since that can't be all it does.

If IBM drives don't have a "disabled" setting, then Maximum Performance would be the same as disabled. If they do have a specific "disabled" setting, then max performance would be when it reduces noise levels as much as possible, without reducing performance too much (which is why I think that more than just the seek speed is involved).