2019 27 inch iMac doesn't wake from sleep when trying to wake using magic mouse or keyboard

[mikehalloran]

PowerNap was enabled by default on my 2019 iMac out of the box so perhaps with that setting left untouched (Enabled by Default) the iMac would never exhibit the deep sleep behavior I’m experiencing but then there’s also the fact that the iMac will never truly sleep if Power Nap is enabled as it keeps some processes running in the background I’m assuming as per the definition of PowerNap in the System Settings Menu (It lets the iMac check email etc while in sleep)

Yes, as far as I can tell, that's the idea since it changed in Mojave.

Battery is very low in my mouse and keyboard about 50%, perhaps that’s another factor to this deep sleep behavior

Maybe but that's easy to test using a wired keyboard if you have one.

Bluetooth does have a tiny latency on wakeup — about 2 seconds (which seems like forever if you're used to a wired keyboard). It shouldn't be more than that, though.

Who needs top save this much energy? can't really be much if you let just the monitor sleep...

Actually, that is a good point. Once I went to an SSD, I never let my iMac sleep—the energy use was so low, <.3Wh, lower than a night light. The monitor, yes. I noticed that the fans went to sleep with the monitor.

Having Power Nap Enabled seems to imitate that earlier setting. Now that I use an iMac Pro, an HDD is no longer the issue. In any case, it, too, is cool to the touch in the morning with the fans shut down. A tap on he keyboard or mouse and I'm back in business.
[doublepost=1562093169][/doublepost]The one other thing is RAM. If you don't have enough free RAM, your Mac will freeze causing you to have to press the Power button to wake it up.

I experienced it with my 2010 if I didn't reboot daily as I only had 32GB onboard. Now that I have 128GB onboard, I'd have to wait 6 days before experiencing it—but I would.

I log into 150 or so sites daily on three monitors while making my living. Between that, Word 2008 and another app, memory leaks are unavoidable. Rebooting only takes me 45 seconds in the morning so I try to make it a habit. Sometimes, I have to do something first thing, then the phone calls etc. and I never get around to it.

 

[Coconutcreampie]

I learned a long time ago, especially as a heavy Home Sharing user, to simply let my iMac run constantly and only have the display turn off after a certain amount of time. With every new version of the Mac OS wake from sleep gets slower and it’s always been problematic in one way or another and when trying to get Home Sharing to work quickly and reliably, especially with external drives.

The cost per month to simply let it run all the time is probably less than $2 a month so I'm OK with that. I also gave up on the external drives and installed an 8TB WD Red NAS HDD in my iMac that is also set to never sleep. As an NAS Drive they are designed to run 24/7. I now get instant access to all my locally stored movies, music and other media to my Apple TV and my iPad, and of course instant display on to the sign in screen.

All that said, my iMac is a late 2012 model running Mojave and I’ve never been unable to wake up from the keyboard or mouse, and not with any other version of the Mac OS.
[doublepost=1562258844][/doublepost]

Yes, as far as I can tell, that's the idea since it changed in Mojave.

Maybe but that's easy to test using a wired keyboard if you have one.

Bluetooth does have a tiny latency on wakeup — about 2 seconds (which seems like forever if you're used to a wired keyboard). It shouldn't be more than that, though.

Actually, that is a good point. Once I went to an SSD, I never let my iMac sleep—the energy use was so low, <.3Wh, lower than a night light. The monitor, yes. I noticed that the fans went to sleep with the monitor.

Having Power Nap Enabled seems to imitate that earlier setting. Now that I use an iMac Pro, an HDD is no longer the issue. In any case, it, too, is cool to the touch in the morning with the fans shut down. A tap on he keyboard or mouse and I'm back in business.
[doublepost=1562093169][/doublepost]The one other thing is RAM. If you don't have enough free RAM, your Mac will freeze causing you to have to press the Power button to wake it up.

I experienced it with my 2010 if I didn't reboot daily as I only had 32GB onboard. Now that I have 128GB onboard, I'd have to wait 6 days before experiencing it—but I would.

I log into 150 or so sites daily on three monitors while making my living. Between that, Word 2008 and another app, memory leaks are unavoidable. Rebooting only takes me 45 seconds in the morning so I try to make it a habit. Sometimes, I have to do something first thing, then the phone calls etc. and I never get around to it.

Odd, I worked just as heavy and more with my late 2012 iMac with 32GB of RAM and never had to bother restarting due to RAM issues.