I wonder, is anyone else experiencing regular wakeups with the new Macbook? Every couple of hours I see: wake reason: ARPT (Network) wake reason: wake on TCP Data I have disabled "Wake for WiFi Network Access" and Power Nap, reset SMC etc and still regularly see these wakes in my syslog. You can do a search for "wake reason" in the console app or run this command in terminal to see when it wakes up: syslog | grep -i "wake reason" Last night I disabled Wi-Fi overnight and it slept without any wakeups so it is definitely related to network access. I had a similar problem on my iMac after upgrading to Yosemite and this was fixed in v 10.10.3 so I wonder if there is a problem with the new Macbook on this OS version. I set up the Macbook from scratch as a new device so it should be a fairly default setup.