10.11.2, Mac Pro will not wake up 4k displays

[Processor]

I have installed 10.11.2 today and found the Mac Pro will not wake up the 4k displays connected to thunderbolt ports. I tried many kinds of 4k displays including u28e590d, u24e590d, p2716q etc, but none of them would wake up after sleep. the only resolution is to unplug and replug the thunderbolt (display port) cable to a different thunderbolt port.
those displays all work perfectly with 10.11 and 10.11.1.

Steps to Reproduce:
1: have a Mac Pro 2013, any configurations and install 10.11.2
2: plug a 4k display like u28e590d to thunderbolt port using mini-displayport cable.
3: let the Mac Pro go sleep
4: when press a key or click the mouse, the Mac Pro will wake up but the 4k display will not wake up.

anyone is experiencing the same problem?

 

[siftinger]

Same for me. Tried 3 monitors. Mini-displayport->displayport, mini-displayport->dual-dvi, and hdmi->hdmi. All 3 monitors have issues. I have to move the cables every time I wake up the monitors.

 

[crjackson2134]

Sounds like it's bug report time (as usual).

 

[pg-robban]

I have the U24E850R connected to a Macbook Pro. Can confirm the problem here and that it started after the update. My other, non-4k screen works fine. Unplugging the 4k display doesn't help, but it does help if I unplug the other screen. I got tired of this so what I do is press cmd+f1 twice (this mirrors the screens and then reverts to extended desktop), and voila, the screen wakes up.

 

[xiter88]

Same problem. It seems as if we have an annoying bug.
Samsung U28D590, when it goes sleeping it doesn't wake up again.
I cleaned the system with Clean My Mac 3, Onyx and reset the PRAM. No way to fix the problem.
I managed to wake it up again by connecting an external HDMI 4K TV but it is of course a workaround.

 

[Scary Spice]

I had this problem with the last beta, but the release 10.11.2 seems fine so far.

 

[klaasjanb]

Same problem here on a 2015 rMBP with Radeon R9 graphics. This is with the 10.11.2 release.
One 4k screen on displayport and an older one on HDMI. After sleep, the 4k screen doesn't go on.
Sometimes, unplugging/replugging the HDMI connector fixes the 4k screen.

 

[kazibole]

No problems (yet) on 10.11.2 with a Dell P2715Q, but I haven't tested it too much.

 

[damezumari]

For me, it seems completely random. I have one displayport 4k display, one HDMI 4k display, and displayport->HDMI fullhd projector connected to nMP. Right now it is in such state that while the machine is running, it has _no_ displays available, and replugging them does not fix it either. Only way to fix this seems to be to use screen sharing + reboot the whole thing. I think soon I will stop upgrading OS X altogether before reading others' comments, as I happily assumed .2 version would be at least moderately usable.. sigh.

 

[damezumari]

One of the screens was 'just' black and had cursor in it. Funnily enough, logging in remotely and kill -9 WindowServer enables the displays but obviously I lose the session I had up. I wonder if I feel motivated enough to restore to 10.11.1 or not, as the backup is relatively old (having faith in Apple, but apparently it was bit misplaced).

 

[h4nc0]

I've reported this bug already when using the last beta. They know about it.

Workaround is disabling monitor sleeping and manually turning off.

 

[klaasjanb]

I just had this problem again and spotted something strange: after unplugging the 4k screen when it won't wake up it's still shown as connected in the system preferences / displays / arrangement tab. Could be the reason it's not woken up when OS X thinks it's still attached and on...

 

[Scary Spice]

I had this problem with the last beta, but the release 10.11.2 seems fine so far.

its baaaaaack....
but very random.

 

[greywolfe]

Same here with Dell p2415q. Don't know about pre 10.11.2 as got display after update.

 

[h4nc0]

Anyone know if this is fixed in 10.11.3 Beta? Let us know. Thx.

 

[damezumari]

Anyone found workaround for this? I have so far stopped normal sleep of my Mac Pro 2013 (it had issues with GPU at least up to 10.11.1 if I turned it on), but even with display sleep turned off, sometimes after I turn the displays back on manually screen is black, cursor moves on the screen but nothing else. *sigh* Remote ssh + killall -9 WindowServer 'fixes' the issue, at least until the next time I am not using it for a prolonged period of time.

It seems somewhat random, does not happen always, but e.g. even after relogin, sometimes my second 4k display goes to that black screen mode immediately. Eventually once the main 4k display also goes, then I do the killall -9 WindowServer after checking via Screen Sharing that I have no state I need to save on the desktop.

 

[reddevil0728]

Same issue here on 2015 MBP with ASUS PB287Q. requires a restart to get it to detect again.

 

[greywolfe]

Can now verify that wake after sleep works with Dell U2515H attached to mid 2012 cmbp running 10.11.2.
Of course this is not a 4K display.

 

[George Dawes]

had the same problem with 2 tv's on two different mac minis 2011 & 2014

el crapitan is so useless , i really hate it

 

[damezumari]

As an additional data point, it seems that SwitchResX worsens the problem for me; without it, if I turn off all energy saving (=system, display sleep), and use manual (display) power buttons, my dual 4k display setup seems to work fine. When SwitchResX does it's thing, the displays start going dead just as if I was using display sleep.

 

[damezumari]

As an additional data point, it seems that SwitchResX worsens the problem for me; without it, if I turn off all energy saving (=system, display sleep), and use manual (display) power buttons, my dual 4k display setup seems to work fine. When SwitchResX does it's thing, the displays start going dead just as if I was using display sleep.

Unfortunately this was too optimistic too; overnight, second 4k display stopped working (although it could handle poweroff+poweron few times during yesterday). Anyone tried 10.11.3 beta? Just using one display (while even one works) feels rather .. sad.

 

[JJayguy23]

This sounds very annoying. Sorry for you all.

 

[HenryAZ]

I use an Eizo EV3237 4k, and a 2013 Mac Pro, and have not experienced this problem. Well, I did, at first (but prior to 10.11.2), until Eizo pointed me to an Administratrive menu where I enabled HPD ("hot plug detect"). Since I changed that setting, a single tap on the space bar brings my monitor back from Energy Saving mode.

One difference that may enter the equation. I do not let my Mac Pro sleep. It's energy use at rest is so small (~78 watts) and it stays quite cool, so I see no need for actual sleep, and it runs 24x7. Only my monitor "sleeps" (goes into power saving mode, where the LED turns orange, the screen blanks, and the power use drops to ~1 watt).

 

[macmania123]

I have the same problem too MBPRO 2015. After I leave my computer idle it puts displays to sleep, then my 4k DELL doesn't wake up.

I have been rebooting the laptop to fix it.

Today I was playing with display settings, and I found when I configured my 4k display to be a mirrored display. Via mirroring options icon in the top menu bar. Can be enabled via display preferences if you don't have it. After the monitor light up, I changed it back to separate displays and it continued to work.

 

[klaasjanb]

Probably a bug in the AMD graphics driver since most of the reporters here are either using a new Mac pro (AMD only) or a MacBook (which probably has AMD graphics). Of all the MacBooks at work nobody using an Intel/nVidia MacBook has this problem.