Go to System Preferences>Energy Saver Set your computer and display to sleep after only 1 minute. Does the computer go to sleep completely or just the display? As some of you may know, I have a sleep problem on my mac pro. One morning I noticed that my computer would not go to sleep... only one of the hard drives would spin up and down constantly. So I tried everything I could to figure out how to fix the problem. I tried unplugging devices, Installing Mac OS X on a different formatted drive, replacing RAM, running Apple Hardware Test, running TechTool Deluxe, resetting PRAM and lastly, I tried resetting the SMC (System Management Controller) and nothing was working. However, while I was testing to see if my computer would go to sleep on it's own, I set it to sleep after only 1 minute to speed up the diagnostic process rather than waiting the full 30 minutes or whatever. Well, today, I was talking to another Mac Pro owner and just for fun I had him try to set his sleep settings to 1 minute... and guess what happened... his computer did not go to sleep, only the display turned off.... interesting I thought. Is this true with all Mac Pros? Could I have fixed the problem LONG ago and not knowing it because of a stupid bug in Energy Saver settings? Please, Mac Pro owners, tell me what happens when you try this.