Wednesday, May 6, 2020

Mac Pros Don’t Really Sleep

Colin Cornaby:

One weird thing about the Mac Pro I haven’t seen mentioned… It does not support sleep. It can do display sleep, and the sleep command in the Apple Menu will trigger display sleep. But the machine itself will not support deep sleep and the fans will always run.

I don’t know if it has its own version of sleep that isn’t deep sleep. Power nap is there. But it doesn’t sleep like other Macs where the fan turns off and the machine is on standby. And if you tap the keyboard to wake it feels like only the display is sleeping.

Brendan Shanks:

Wow, power usage in “sleep” is 15W, that’s really high. iMac is 1W, even trashcan Mac Pro was 4W.


Update (2020-05-06): John Siracusa:

You can absolutely get a 2019 Mac Pro to sleep and spin down all its fans. Use the pmset command-line tool to find out what’s keeping your Mac from sleeping.

Colin Cornaby:

Ohhhh interesting. Sharingd and powerd were preventing sleep even though no one was connected? Turned screen/file sharing off and then back on again, and now after about a minute the fans spin down all the way.


Mine turns on the rear blower after about 90 minutes of sleep. It’s barely audible but you can feel the air flow. I wonder if this behavior is normal?!

8 Comments RSS · Twitter

Ben Kennedy

How much idle power do the wheels use? 😜

Jesus, of course the Mac Pro supports actual standby sleep.

Nathanaël Havez

Is it just me or are there real issues with power management on Catalina ? (Forcing ya to go through pmset most of the time)

Like, reading this reminded of my daily wake-up crashes on my MacBook Pro 15” 2018. And they’re real pain in the ass.

Just a bug, clearly, but a bug nonetheless. @Siracusa telling @Colin to disable features that should not be preventing sleep is great for troubleshooting but still a bug. "Wake for Network Access" should require active access by a device sending a magic packet (yes, I know many OS X services will send the packet automagically from a client device).

The way I tested my sleep problem way back in the mid 2000s on an older Power Mac G4 was to disable certain features and disconnect certain devices from the network. This gigabit Power Mac G4 (Mystic?) would wake essentially every hour (almost exactly) if connected via FireWire with networking enabled (anyone remember when you could network via FireWire?), but would sleep fine with Ethernet. Seemed like a bug to me. As long as the cable was connected, did not seem to matter what was happening on the network, FireWire would wake the system regularly.

Apple should figure this out, assuming an actual bug because from my experience, it will drive you batty.

It looks like this "non-sleeping" is the reason many 16" MBP's are crashing so often, or at least a big contributing factor

New Mac Pros do sleep, but like their predecessors, they can't do it RELIABLY because of — what else is new — software bugs.

In my experience, when it does work, sleep can cause the Mac to randomly eject volumes connected via Thunderbolt. Reported that bug years ago to Apple for the 2013 Mac Pro. Nothing's ever been done as far as I can tell. I prevent my Mac from sleeping just to avoid this, and consume electricity for nothing.

Apple is only ecofriendly as long as it doesn't involve making sure their software is bug-free. (After all, bugs are an essential part of the environment.)

Wait, the 16" MBPs are crashing? Interesting if also power related.

Sören Nils Kuklau

Wait, the 16” MBPs are crashing?

10.15.4 seems to have introduced a common kernel panic.

Some have suggested that disabling PowerNap resolves it. For example.

Leave a Comment