After doing some research and finally getting HDAPM fully installed and working I decided I'll write up a little guide to help others get it up and running. I will do the guide step by step so even dummies can do it. If you don't know what HDAPM is, its a program developed to edit the APM (power settings) of the drive. OSX has a nasty habit of parking the drives heads every few seconds making either a noticeable or even an unnoticeable click. This also causes the load cycle count of the drive to increase rapidly. Most drives are rated to live at least up to 600,000 load cycle counts. Without HDAPM some drives can easily put on 10,000 load cycles in a week. This is a problem IMO. These are the instructions to get HDAPM installed on your ‘optibay’ HDD (MBP users who put a HDD in their optical bay), but if you want to install it on your normal drive just don’t replace disk0 with disk1 on step 5. 1. Download and install HDAPM - hdapm Download page 2. Open finder and press apple + shift + g 3. Type /Library/LaunchDaemons/ 4. Find hdapm.plist and open in with text edit 5. Find where it says <string>disk0</string> and replace the 0 with a 1 6. It will ask you if you want to duplicate the file, select yes 7. On the duplicate make sure it says <string>disk1</string> 8. Then where it says <string>max</string>, replace that with <string>195</string>. This sets your APM to 195 out of 254 (max) which stops the drive from clicking and racking up load cycle counts, but also allows it to save battery and sleep (max setting sometimes will not let the drive sleep) 9. Save to desktop as hdapm.plist 10. Drag and drop the hdapm.plist on your desktop into /Library/LaunchDaemons/ 11. Replace the existing file 12. Open up terminal and enter this command (this makes it so hdapm loads up every boot): sudo chown root:wheel /Library/LaunchDaemons/hdapm.plist 13. Reboot your Mac 14. Open up console in Utilities and search HDAPM, it should list the drive you selected and states “success” Now to save some more battery download cocktail and set your HDD to sleep after about 5 minutes. This is a nice happy medium where you will save battery but not drastically increase load cycle counts (sleeping the drive often will cause load cycle counts to rise).