I have been experiencing intermittent difficulties getting my display to wake up. This is an old Apple Cinema Display that has been used on a PowerMac G5 and a MacPro for many years. It is now attached to my M2 Mac Studio using a DVI to USB-C connector. The display works fine – except when it does not wake up.
There are numerous threads on various fora concerned about displays not waking on various Apple Silicon devices (maybe Intel, too).
I’ve included the log from pmset below. I hit several keys (space, shift, esc) and those failed to wake up the display–but there are some interesting entries about drivers/etc being slow. I then disconnected the USB-C cable (shown as a break in the log). There might be something useful here.
Thanks.
2025-02-03 10:16:19 -0700 Wake Wake from Deep Idle [CDNVA] : due to SMC.OutboxNotEmpty smc.70070000 usb3 pcie-xhci/UserActivity Assertion Using AC (Charge:0%)
2025-02-03 10:16:19 -0700 WakeDetails DriverReason:SMC.OutboxNotEmpty - DriverDetails:
DriverReason:smc.70070000 - DriverDetails:
DriverReason:usb3 - DriverDetails:
DriverReason:pcie-xhci - DriverDetails:
2025-02-03 10:16:19 -0700 HibernateStats hibmode=0 standbydelaylow=0 standbydelayhigh=0 4
2025-02-03 10:16:19 -0700 WakeTime WakeTime: 0.725 sec
2025-02-03 10:16:19 -0700 Kernel Client Acks
2025-02-03 10:16:19 -0700 Kernel Client Acks Delays to Wake notifications: [Port-USB-C driver is slow(msg: SetState to 1)(86 ms)] [AppleDCPDPTXRemotePortProxy driver is slow(msg: SetState to 1)(81 ms)] [usb-drd1-port-hs driver is slow(msg: SetState to 3)(105 ms)] [RTBuddy(ANS2) driver is slow(msg: SetState to 2)(174 ms)] [AppleT6020PCIe driver is slow(msg: SetState to 2)(290 ms)] [IOPP driver is slow(msg: WillChangeState to 2)(202 ms)] [pci-bridge2 driver is slow(msg: SetState to 2)(202 ms)] [AppleConvergedIPCOLYBTControl driver is slow(msg: SetState to 1)(494 ms)] [AppleMultiFunctionManager driver is slow(msg: SetState to 1)(494 ms)] [AppleCS42L84Audio driver is slow(msg: DidChangeState to 1)(535 ms)] [Codec Output driver is slow(msg: WillChangeState to 1)(535 ms)] [AppleEmbeddedUSBXHCIASMedia3142 driver is slow(msg: WillChangeState to 2)(330 ms)] [AppleEthernetAquantiaAqtion113 driver is slow(msg: SetState to 2)(159 ms)]
2025-02-03 10:16:19 -0700 Assertions PID 115(powerd) Created InternalPreventSleep "com.apple.powermanagement.acwakelinger" 00:00:00 id:0x0xd0000a22d [System: PrevIdle DeclUser SRPrevSleep kCPU kDisp]
2025-02-03 10:16:19 -0700 Assertions PID 170(WindowServer) Created PreventSystemSleep "com.apple.WindowServer.PUIDS" 00:00:00 id:0x0x70000a231 [System: PrevIdle PrevSleep DeclUser SRPrevSleep IPushSrvc kCPU kDisp]
2025-02-03 10:16:19 -0700 Notification Display is turned on
2025-02-03 10:16:19 -0700 Assertions Summary- [System: PrevIdle PrevSleep DeclUser SRPrevSleep IPushSrvc kCPU kDisp] Using AC
2025-02-03 10:16:19 -0700 Assertions PID 170(WindowServer) Released PreventSystemSleep "com.apple.WindowServer.PUIDS" 00:00:00 id:0x0x70000a231 [System: PrevIdle DeclUser SRPrevSleep IPushSrvc kCPU kDisp]
[pulled usb-c cable; reinserted]
2025-02-03 10:17:04 -0700 Assertions PID 115(powerd) TimedOut InternalPreventSleep "com.apple.powermanagement.acwakelinger" 00:00:44 id:0x0xd0000a22d [System: PrevIdle DeclUser SRPrevSleep kCPU kDisp]
2025-02-03 10:17:04 -0700 Assertions Summary- [System: PrevIdle DeclUser kDisp] Using AC
2025-02-03 10:31:12 -0700 Assertions PID 44669(sdbackupbytime) Summary PreventUserIdleSystemSleep "sdbackupbytime Smart Wake" 00:00:07 id:0x0x10000a7ad [System: PrevIdle DeclUser kDisp]
2025-02-03 10:31:12 -0700 Assertions PID 115(powerd) Summary PreventUserIdleSystemSleep "Powerd - Prevent sleep while display is on" 00:14:53 id:0x0x10000a232 [System: PrevIdle DeclUser kDisp]
2025-02-03 10:31:12 -0700 Assertions PID 115(powerd) Summary UserIsActive "com.apple.powermanagement.kernel.useractive AppleUserUSBHostHIDDevice:kIOHIDSystemActivityTickle NX_HARDWARE" 00:14:53 id:0x0x90000a22c [System: PrevIdle DeclUser kDisp]
2025-02-03 10:31:12 -0700 Assertions PID 170(WindowServer) Summary UserIsActive "com.apple.iohideventsystem.queue.tickle serviceID:100000d6b service:AppleUserHIDEventService product:USB Optical Mouse eventType:17" 00:00:00 id:0x0x900009bc8 [System: PrevIdle DeclUser kDisp]
2025-02-03 10:31:19 -0700 Assertions PID 115(powerd) TimedOut UserIsActive "com.apple.powermanagement.kernel.useractive AppleUserUSBHostHIDDevice:kIOHIDSystemActivityTickle
Edit: I am currently using this DVI to USB-C adapter to connect the display to the Studio.
I read that and dozens of other discussions online but could not find any definitive solutions. That is why I posted a portion of the log so that a reader could look at it and provide some information.
and the problem went away for about a week. It has since returned. As mentioned in the original post I am using the Startech DVI to USB-C adaptor. I have to resort to unplugging the USB-C connector to get the display to work.
I was able to Screen Share with the Mac Studio – indicating to me that it was definitely the display sleeping and not the Mac. Remotely I was able to reset nvram and then reboot – so that’s an option. Although it might simply be easier to hold the power button for 10 seconds and reboot the Studio that way.
I still have not determined if the problem is the M2 Studio or the hardware DVI-to-USB that is the problem.
I find odd that there seems to be so many issues with Macs waking up from sleep, or should I say with recent macs (Apple Silicon and recent versions of MacOS X). I don’t remember having such problems myself with my Intel-based MBA or seeing other people having similar problems “back in the day”.
Is it me or are “waking up from sleep mode” issues more prevalent with current/recent vintages of Macs? BTW, it’s not just display issues, it’s also “USB Accessories Disabled” ones. Again, never saw this before I upgraded from Intel to Apple Silicon.
@david_blanchard: do you have an intel-based Mac you can test to see if you have the same kind of issue?
Originally the Apple Cinema Display was connected to an Intel MacPro5,1 and it would wake from sleep instantly. I moved the ACD to my M2 Mac Studio and have to use a DVI-to-USB adapter. Either the Studio or the adapter could be the problem. If I reconnect it directly to the MacPro it works fine.
Oh, it was using a video card, possibly a double output one?
I see the pattern that you’ve started experiencing issues with your display once you got an Apple Silicon machine. Pretty much like me, after I went from an Intel-based Mac to an AS one. Either a sleep-mode related bug appeared in recent versions of MacOS, irrespective of CPU architecture, or the mix of recent MacOS X & Apple Silicon is the cause of this bug.
I’m still experiencing sporadic issues related to wake-up from sleep, so I’ve started to shut down my Mac instead of putting it to sleep at the end of the day. Because of the power button thing with the new M4 Mac Mini, methinks Apple should start looking seriously at this general issue, because it’s going to start hurting their image of “it just works”.
The problem with the display not waking continues but I have found a less disruptive way to wake things up.
On the Mac Studio I press and hold the power button for 1-2 seconds. This brings up a dialog box with options for Restart, Sleep, Cancel, Shut Down. Shut Down is the default but typing the letter S puts the Studio in Sleep mode. Wait about 5-10 seconds and then hit any key to wake up the Studio which also wakes the display. The nice thing about this method is I can do it even if I cannot see the display. So there is no need to pull the USB-C cable out anymore.
But I would like to see a way to prevent the problem.
I purchased the Apple 27" Studio Display and there is no longer a problem. The display wakes up instantly–just the way the Apple Cinema Display wakes when used on the Intel MacPro.
It’s difficult to determine the root cause of the problem: it could be the display, the adaptor, or the M2 Studio. But I also had issues with an older Apple USB keyboard with the M2 Mac Studio so there may be reasons to believe that Apple Silicon is not fully compatible with legacy Apple products.
I’ve been having a related, but slightly different, problem for well over 2 years now.
M1 Mac mini, always with the latest release of macOS. Two Dell 4k monitors, one connected via HDMI and the other with a high-quality Belkin HMDI to USB-C adapter going into a thunderbolt port.
Roughly 30% of the time when waking the Mac from sleep, or 10% of the time when powering on the Mac, the monitor using the adapter either never fully wakes or wakes with the proper wallpaper, dock, etc. for a few seconds and then goes dark. I have to unplug from the thunderbolt port and plug back in to fix the problem.
It’s really maddening, especially considering that the same two monitors never have the problem when connected to a Windows pc.
I don’t know if it’s the cause of your problem, but have you tried using a DisplayPort connection?
If your Dell display has a DP or mini-DP port, try using that (with a suitable cable: USB-C to DP or USB-C to mini-DP) and see if that changes anything.
I ask because USB-C alternate display mode is DisplayPort. It is supposed to be compatible with HDMI, but the two protocols are not identical. So maybe DP will work better.
I already have a regular DisplayPort cable connected to the monitor (and my Windows PC). As I’m not really using the pc anymore, what would you think about unplugging it from the PC and then adding a USB-C to DP adapter to go to my Mac (rather than a dedicated USB-C to DP cable)?
I ask because it’s rather difficult to access the port on the monitor, so it’s a whole lot easier to just add an adapter to the existing cable.
If it works, or looks promising, I’d suggest later switching to a cable without an adapter, because every mechanical connection on a cable results in some amount of signal degradation, which can be critical with high-frequency signals like those used for 4K video.
Also, consider using the shortest-length video cable you can. If the display is close enough so you can use a 1m cable, then that will be more reliable than a 2m or 3m cable.
Also, make sure to use high quality cables. Cheap ones may not be able to deliver a clean 4K video signal. I linked to Cable Matters, which has a good reputation. There are other good brands, but there are also a lot of really bad ones.
Back in the days of analog video (e.g. VGA or Apple’s old 15-pin D-shell connector), a degraded video signal would result in video noise or ghost images or other artifacts. But with digital video, when the signal degrades, you end up with a black screen.
Tried the corresponding Cable Matters adapter, but my screen went briefly black every 12 seconds. That’s worse than my existing problem, so I’m back to HDMI with the Belkin adapter (I’m not up to trying the full cable swap now).
It definitely sounds like you aren’t getting a clean-enough signal.
It may be that your cable and/or adapter can’t pass the higher frequencies needed for 4K video.
According to Wikipedia, a 4K image at 60 Hz requires a 14.4 Gbit/s data rate (introduced as a part of the HDMI 2.0 spec).
Similarly, for DisplayPort, 4K at 60 Hz requires the “HBR2” (17.28 Gbit/s) data rate (introduced in DisplayPort 1.2).
If your cable or adapter are not able to reliably handle these high data rates, an unstable picture like you are seeing would be a likely result. So when shopping for replacements, it is critical to check these specs. I’d look for cables/adapters that are certified to handle these speeds. And be wary of el-cheapo brands, since they may lie about certifications and specifications.
A “Premium High Speed HDMI” cable (aka “category 2 premium”) is certified up to 18 Gbps, and can therefore handle 4K at 60 Hz.
Higher-frequency certifications (if you think you might need compatibility with higher resolutions, bit-depths, refresh rates or other features in the future) are:
"Ultra High Speed HDMI ", aka “category 3” (48 Gbit/s, which can handle 5K at 110 Hz)
“Ultra96 HDMI” (96 Gbit/s, which can handle 8K at 100 Hz or 10K at 76 Hz)
The slower “Standard” and “High Speed” cable types top out at 4.95 and 10.2 Gbit/s, respectively and therefore can’t reliably handle 4K at 60 Hz, although they would work fine for 1080p and “High Speed” would work fine for 1440p.
Any VESA-certified DisplayPort cable should be able to handle RBR, HBR and HBR2 data rates, and should therefore be compatible with 4K at 60 Hz.
Higher-frequency certifications are:
“DP8K” for HBR3 (25.92 Gbit/s - 4K at 120 Hz or 5K at 60 Hz)
“DP40” for UHBR10 (38.68 Gbit/s - 5K at 102 Hz)
“DP54” for UHBR13.5 (52.22 Gbit/s - 5K at 136 Hz. 8K at 63 Hz)
“DP80” for UHBR20 (77.37 Gbit/s - 8K at 92 Hz)
Of course, you can get good cables without certification, but then you’re relying on the manufacturer’s word that the cable can support these data rates. Probably OK for a known reliable brand, but not something I’d blindly trust for a brand I’ve never seen before.
Well, the adapter I got is made by Cable Matters, and they say it can support 4k @ 240 Hz. And the cable itself is identical to the one going straight into the Mac mini’s HDMI port (which doesn’t have the original problem). Since I’m only running my 4k monitors at 60 Hz, I would think I’m clearing the bar on everything you mentioned.
