Q: with 10.11.2, Mac Pro 2013 will not wake up 4k displays after sleep like before.

Hopefully that fixes it. By the sounds of it my setup is similar to yours.

The CMD + F1 and CMD + F2 trick has become less and less reliable for me. I've had to switch ports a couple of times to get my monitors back working.

Has anyone tried downgrading and if you have want are good methods of doing so? My Macbook Pro is still running 10.11.1 and I've considered just formatting and restoring from it's drive.

It's like a joke. 4000 dollars computer and each time I need plug and unplug a cable and no one from apple even bother to answer. Before buying Mac pro I had a hackintosh computer it was working much better that this trash can. It was my biggest mistake to buy this over priced computer.

The latest dev seed / public beta appears to fix this problem, at least for me (Samsung UD970 4k + 2 Apple Cinema).

Definitely still broken for me . It isn't 100% reproducible like it was, but only my 4k display comes back awake every time. The Asus PB278q seems to come back about 50/50.

Bummer. My issue was that the 4k monitor would _never_ come back online, while the other lower resolution screens did. Sounds like it's very configuration dependent.

After posting here my problem with 10.11.2 MacPro Late 2013 and 2x Samsung 4K U32D970 (the problem with not waking up appeared after the update to 10.11.2 !! - before it was perfect), I got an Beta Invitation and installed the 10.11.3 Beta 2 (Built 15D13b) and happy to say that my problem seams to be FIXED now with this 10.11.3 Beta - So I guess after the next 'official' 10.11.3 Fina Update the Problem should be gone. Meanwhile the Beta 2 fixes the problem... at least after using it for a day now... Did`t had any issues with the Beta 2 yet.... but as always with beta software "your milage may vary".... just to let you know that the bug should be fixed soon, and could be fixed via installing the beta.

Beta 2 also fixed it for me with one 28,5-Zoll (2560 x 1080 via display port) and a 21,5-Zoll (1920 x 1080 HDMI) connected to AMD Radeon HD 7950 3072 MB

On a classic Mac Pro 5.1

Can you tell us how we can download the beta 2? It appears that I need to be signed up as a developer? Unplugging and plugging back several times really is getting my head in...

google for el capitan public beta

Half-assed solution:

This has been a constant headache for me since original purchase.  As with others, it seemed to get worse with 10.11.2, i.e. consistently won't wake up and forced me to do a reboot.  I've found a work around that consistently works for me now:  punch the power button 6-8 times repeatedly.   Wakes up, at least for me.  Silly for a $4k+ setup, but works for now (and nothing else does, again, for me). 

Well, 10.11.3 improved my wake-up situation slightly, BUT! 10.11.4 seems to have solved this issue.

I'm on Mac Pro with D700's and 2 4K monitors (Philips 288P6 and Samsung U24E590).

/Kim Bjoern

Yeah, I found it happen after that upgrade as well.

Has anyone found if changing out cables to higher quality ones has helped at all? I have two Samsung U28D590D's and I've been doing some researched and it sounds like some Windows people have been having this same problem also and that changing out cables fixed it.

I'm personally starting to think that the problem is with my monitors themselves rather than my Mac or OSX. (Yay I guess?). Seems like it's a known issue with my monitors that they won't wake from sleep and Samsung knew about the problem and didn't stop selling them.

Has anyone found if changing out cables to higher quality ones has helped at all?

Wow, this whole thing is such a tangled mess!

I've been down this road with my 2 Dell 4K UP2414q's. I saw some posts on a forum last summer that linked to these cables: http://www.amazon.com/gp/product/B00A7R9I22

Some people there (please, read the reviews, they are enlightening) implied that these cables were the saviour for waking unresponsive 4K monitors. Well, I bought 2 of them and they really didn't change anything, at least not for the Dells.

BUT, I recently bought an HP z27q (5K) monitor and lo and behold, they are the only cables that allow the z27q to show a picture at all (!!) on my MacPro (2013 running 10.11.2).

I tried using the 2 cables that came with the Dell 4Ks and...nothing. No picture. Just a black screen. The instant I switched to the Accell cables, the 5K sprung to life in glorious 5K, 60Hz. SO weird. How can it be that brand new cables of the same type (Mini DP to DP) can perform so differently?

I have no idea whos fault this mess is, but the answers are very dependent on cable, monitor make and model, the number of monitors (more than one Dell 4K hooked up was always worse as far as wake/sleep issues)

Just as an aside, the HP 5K is a nice monitor, but not without some issues. It doesn't seem to have any of these wake/sleep issues -- but, there is a reason that the panels are so cheap and that is because that HP cuts some corners in the manufacturing of the panels. My panel itself is perfect, no dead/stuck pixels, but there are a few (very small, admittedly) specs of crap behind the lcd and in front of the backlight. My particular unit has 2 pencil-dot sized specs, one in the lower left, the other in the upper right. Of course, once you see them, you cant unsee them. Annoying, but the panel itself is quite nice. It seems to be the only 5K with a pure matte finish which I need as an artist (I really hate glare). The warranty period is good (3 years), so I can use it for a while and then have HP replace if I feel driven to. Some folks have replaced 4 or 5 times to no avail (same issues), so for now I'm not gonna do anything.

There you have it... riding the bleeding edge can be bloody miserable.

The cables are a red herring. My dell and Samsung 4K monitors worked fine for a year, and now no video at all (I'm running FileVault) from my Mac Pro. But if plug these monitors with the same cables into my MacBook Pro, I have perfect support, video, sleep, etc. (since my Mac Pro is now a paperweight, I bring my MBP home from work on a regular basis).