This TIP for system maintenance and performance has been verified to be legit by Apple Support. I called them before trying it and they said it IS a legitimate thing to do, however to be careful when doing it. PLEASE, I mean it, PLEASE read this entire post before doing this TIP. I am not responsible for your errors! For all our Mac users...I have a trick for you if you seem to be noticing a decrease in system performance. There are some built in scripts that are supposed to run at a certain time (time varies by machine). If your machine is not running when these scripts are scheduled to run, they simply won't run. Try running them manually by entering the following in "Terminal" on your machine: sudo periodic daily weekly monthly This runs all three of the system maintenance scripts manually. You can run these individually as well via: sudo periodic daily sudo periodic weekly sudo periodic monthly PLEASE NOTE! DOUBLE CHECK YOUR TYPING BEFORE HITTING ENTER! A simply typo CAN cause a LOT of problems for you. For those of you who know *NIX operating systems, "sudo" is a VERY, and I repeat, VERY powerful command and can wreak havok on a system. So please, if you decide to use this TIP, do so with caution as I am not responsible for your user error. Once again, DOUBLE CHECK your typing before you hit enter and make sure it is typed 100% correctly. After hitting enter, it WILL ask for your administrator password, this is to ENSURE that you are sure about doing this command, and also gives you ONE LAST CHANCE to check your typing.