I just bought a 5k iMac yesterday, and I notice that the Energy Saver settings in El Capitan no longer have "computer sleep", only "turn off display after:" and a minutes slider. Also, I disable Power Nap. On my El Capitan 2012 MacBook Air, it's still there. But not on this iMac, which is the Skylake CPU and a 1TB SSD. So I am now curious as to what "sleep" means on this computer now. Does it just sleep when the screen is off? Or I also read that when the computer is idle, there's no reason to sleep anymore as it uses so little power? I have some Chronosync jobs that are supposed to run overnight and wake the computer to do so, but now there's no real way to know when the computer will sleep again, or if "computer sleep" is now coupled with "display sleep" 100%. I've Googled around quite a bit, and I am not sure if this is totally new with the 5k Skylake iMac. I've attached what it looks like. I can't be the only one to be curious about this, has anyone else found the real explanation?