Its on a lot of makes of HDD's but not all, its a way of making the seek arms slower so quieter, I see no point in buying a Raptor for quietness so no point in AMM being on by default, grab the Hitachi feature tool from their main site as its only one to see SATA HDD's, I used to use old IBM tool which had some 3rd party name on maxtor EIDE's HDD'S but it cant see SATA HDD's
Basically boot to the floppy, or bootable .ISO and follow on screen info till you at the Raptor and you can do lot of stuff but I dont think turning off SMART stays off or does much for gaining speed so only mess with AMM, also dont touch your read or write cache, its myth about turning one or both of to gain anything your HDD will be major slow take it from me, I had a cache chip die on me once and PC was slow and it took me days to work out what was wrong.
You can set AMM to any setting from off to diff specs in between on or off then hit TEST button and you will hear how loud it is at current setting, my Raptor aint louder now but if it seeks it will rattle away but I dont mind I wanted speed not a job in a libary.