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AdrianT

macrumors member
Original poster
Nov 19, 2009
50
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Just got the nMP with two monitors connected, a 4k at 3840x2160 via miniDP to DP and an old 27" at 1920x1080 via miniDP to DVI.

One thing really annoying is whenever the MP sleeps or I invoke sleep via a hot corner and the displays go into powersave mode, I'll wake it up again and the windows on the 4k display all resize upwards to fit into the 1080p monitor's resolution.

This happens everytime when waking up, windows all resize to half their size vertically on the 4k monitor and I have to resize and pull them down again. Any ideas how to fix this?
 
Just got the nMP with two monitors connected, a 4k at 3840x2160 via miniDP to DP and an old 27" at 1920x1080 via miniDP to DVI.

One thing really annoying is whenever the MP sleeps or I invoke sleep via a hot corner and the displays go into powersave mode, I'll wake it up again and the windows on the 4k display all resize upwards to fit into the 1080p monitor's resolution.

This happens everytime when waking up, windows all resize to half their size vertically on the 4k monitor and I have to resize and pull them down again. Any ideas how to fix this?

Sorry, I wish I had a 4K monitor to try and recreate this problem :)
 
A long shot, but maybe check to see if the monitor has any power settings that after put to sleep, disabled it enough that it no longer is recognized by the nMP.

If you manually turn the monitor on and off, does it resize everything to 1080p like when it comes back from sleep?

I have a Dell 30" u3014 display on a MacBook Pro Retina connected by Display Port. The darn monitor locks up when going to sleep half the time. I'm forced to turn it off, which disconnects it from the mac, and resized everything to the top quarter of the monitor.

Sometimes a true Display Port monitor can be really annoying.
 
I've figured the problem seems to be the old DVI monitor wakes/powers up faster than the new 4k monitor. So when the old monitor wakes up, all windows are transferred over there, then the 4k monitor wakes and moves the originally windows back which then resizes all of them to fit into the old monitors screen.
 
I'm having exactly the same issue with my new Mac Pro and ASUS PB287Q. I have the UHD 4K monitor hooked up, as well as an HD BENQ projector. You're probably right that it's resizing for the projector first before it notices the 4K monitor. It's got to be fixable by Apple. I hope they update this soon. They need to get on the ball with the new 4K monitors that are coming out. I'm still having tearing issues with the PB287Q on the right side of the panel.
 
Same issue

I currently own a mac and a windows machine, and I'm having this exact problem on my windows machine with the ASUS PB287Q. I haven't tested on my mac considering it does not support 4k @ 60Hz.

I will note that no other monitor is hooked up to my machine, and this happens after going to sleep AND after I turn it off and on.

After reading this thread it makes me think it has nothing to do with the OS and more to do with the monitor. I have dug through all windows settings and came up with nothing.

I found 1 review on amazon with someone having this issue: http://www.amazon.com/review/R2PP2OUQ0JUM0V/ref=cm_srch_res_rtr_alt_1

I will update if I find a resolution.
 
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I currently own a mac and a windows machine, and I'm having this exact problem on my windows machine with the ASUS PB287Q. I haven't tested on my mac considering it does not support 4k @ 60Hz.

I will note that no other monitor is hooked up to my machine, and this happens after going to sleep AND after I turn it off and on.

After reading this thread it makes me think it has nothing to do with the OS and more to do with the monitor. I have dug through all windows settings and came up with nothing.

I found 1 review on amazon with someone having this issue: http://www.amazon.com/review/R2PP2OUQ0JUM0V/ref=cm_srch_res_rtr_alt_1

I will update if I find a resolution.
I cannot help with the problem, but I believe that your monitor can run 4K @ 60 Hz in Yosemite :)

I've seen this confirmed by a couple of users.
 
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Same issue here with Mavericks/Yosemite on Mac Pro 6,1 and Samsung U28D590 4K Display running at 60Hz over Mini-DisplayPort (Male) to DisplayPort (Male) Cable.

Res is set to 3008 x 1692, and when Display Sleep is invoked automatically, or via Hot Corner, or via  > Sleep, all large windows are resized to 1280 x 952 and sent to the top-left corner.

I've noticed that when invoking Display Sleep by Hot Corner or  > Sleep, if I wake the screen before the monitor fully turns itself off (after ~7 seconds), the windows are not resized. The issue occurs only when the display fully turns off.

Next I will try setting the monitor's own power settings to power off after 1 hour (which is the minimum), and setting the Mac to never turn off the display in Settings > Energy Saver.
 
I have a sneaking suspicion that my Mini-DisplayPort (Male) to DisplayPort (Male) Cable might be causing this, but I won't be able to tell until my cable company send a new cable that is capable of better bandwidth. They have found that the current cable is not fully able to send 4K @ 60Hz. The issue I first had was that my 4k monitor screen flickers for a half a second, at random intervals every 5 or so minutes.

You wouldn't think this would be related, but the more things I try, the more I suspect it is.

Case in point: I just noticed today that if I use HDMI - this window resize issue completely disappears. I can go to full 4k, sleep and wake, turn the monitor off and on, and all windows stay in their position and size. But HDMI can only give me 30Hz so that is rubbish.

But then if I try with the DP cable - every one of the five available resolutions have the sleep/wake window resize/reposition issue. It also happens if I disconnect the DP cable and reconnect it.

Apple are also researching this so if I hear anything from them, I'll update you here.
 
I have a sneaking suspicion that my Mini-DisplayPort (Male) to DisplayPort (Male) Cable might be causing this, but I won't be able to tell until my cable company send a new cable that is capable of better bandwidth. They have found that the current cable is not fully able to send 4K @ 60Hz. The issue I first had was that my 4k monitor screen flickers for a half a second, at random intervals every 5 or so minutes.

You wouldn't think this would be related, but the more things I try, the more I suspect it is.

Case in point: I just noticed today that if I use HDMI - this window resize issue completely disappears. I can go to full 4k, sleep and wake, turn the monitor off and on, and all windows stay in their position and size. But HDMI can only give me 30Hz so that is rubbish.

But then if I try with the DP cable - every one of the five available resolutions have the sleep/wake window resize/reposition issue. It also happens if I disconnect the DP cable and reconnect it.

Apple are also researching this so if I hear anything from them, I'll update you here.

Jayden....seeing exactly the same issues as you. Could you elaborate on the models/manufacturers of cables that you were testing with?
 
Jayden....seeing exactly the same issues as you. Could you elaborate on the models/manufacturers of cables that you were testing with?

This is the cable I have: http://www.cablechick.com.au/cables...le-to-male-thunderbolt-socket-compatible.html

Cablechick in Australia have offered to replace it for no additional cost when they have a better cable in stock. They've been great to deal with about it. So until I get a better cable, this is all the info I have at this point.
 
It is Apple 'feature', both in Mavericks / Yosemite. I have two 4k displays (Asus PB287Q, Dell UP3214Q), and it happens at least sometimes to both of them.

(I think the problem happened less or maybe not at all if I used HDMI, but then it's hello 30hz).

Stay ( http://cordlessdog.com/stay/ ) can fix the problem for the windows you care about, and especially in a multi-window setup I consider it essential in any case. Every time I toggle on my projector, the layout of windows gets screwed due to automatic display mirroring (.. sigh, Apple ..), and it fixes that too.

But speaking of annoying problems, anyone have issues with DP monitors not working on boot? I have finally given up and plugged the Asus to HDMI port (and live with 30hz) to be able to have monitor that I can actually log in on.. :p
 
This is the cable I have: http://www.cablechick.com.au/cables...le-to-male-thunderbolt-socket-compatible.html

Cablechick in Australia have offered to replace it for no additional cost when they have a better cable in stock. They've been great to deal with about it. So until I get a better cable, this is all the info I have at this point.

So I got this cable, which has 21.6Gbps bandwidth and it still has the same issues!

http://www.startech.com/Cables/Audi...playPort-Adapter-Cable-Male-to-Male~MDP2DPMM6

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It is Apple 'feature', both in Mavericks / Yosemite. I have two 4k displays (Asus PB287Q, Dell UP3214Q), and it happens at least sometimes to both of them.

(I think the problem happened less or maybe not at all if I used HDMI, but then it's hello 30hz).

Stay ( http://cordlessdog.com/stay/ ) can fix the problem for the windows you care about, and especially in a multi-window setup I consider it essential in any case. Every time I toggle on my projector, the layout of windows gets screwed due to automatic display mirroring (.. sigh, Apple ..), and it fixes that too.

But speaking of annoying problems, anyone have issues with DP monitors not working on boot? I have finally given up and plugged the Asus to HDMI port (and live with 30hz) to be able to have monitor that I can actually log in on.. :p

When you say not working on boot, do you mean that the login screen doesnt appear there? I see a background, but not the user login prompt on my mirrored external DP monitor.
 
When you say not working on boot, do you mean that the login screen doesnt appear there? I see a background, but not the user login prompt on my mirrored external DP monitor.

No sync at all on the DP monitors. Only on HDMI one. If I remove all cables except one DP, it sometimes works, but most of the time not. HDMI works always. Sigh. In the end I just keep my Asus PB287Q plugged to HDMI port, and Dell to DP; I can live with 30hz on secondary monitor more than I want to live with re-plugging cables every time I reboot the machine (or it fails to resume from standby, sigh).
 
Weird, does it happen on both Dell and Asus? Have you tried a different DP cable? I have a Samsung 4k and haven't had any problems on the login screen after boot, just the windows resizing which has been (somewhat) alleviated with Stay.
 
Weird, does it happen on both Dell and Asus? Have you tried a different DP cable? I have a Samsung 4k and haven't had any problems on the login screen after boot, just the windows resizing which has been (somewhat) alleviated with Stay.

I'm seeing quite a few posts in various places about the flicker / screen blackout every few mins. Quite a few thinking its cable related, but it doesnt appear to be bandwidth based on the cable I'm using. Has anyone actually found a cable that eliminate the problem?

To add to my confusion, I also found this....which makes me think that my monitor (Samsung U28D590D) may not be supported with 60Hz connection. Could this also be part of the problem?
http://support.apple.com/en-ie/HT202856

Sigh....I thought life with a 4k monitor would be great....
 
Weird, does it happen on both Dell and Asus? Have you tried a different DP cable? I have a Samsung 4k and haven't had any problems on the login screen after boot, just the windows resizing which has been (somewhat) alleviated with Stay.

It mainly happens only if I have more than one device connected. With Dell only, it happens sometimes, with Asus only I haven't tried much and can't remember how often if at all. (It is secondary monitor so not using it much.)

----------

To add to my confusion, I also found this....which makes me think that my monitor (Samsung U28D590D) may not be supported with 60Hz connection. Could this also be part of the problem?
http://support.apple.com/en-ie/HT202856

Sigh....I thought life with a 4k monitor would be great....

Yosemite silently added support for number of other DP 1.2 SST monitors too (at least for D500/D700 Mac Pros, which apparently had issues in the display driver in Mavericks). For example, my Asus PB287Q did not work in Mavericks in 60hz (weird stuff happening on right edge of screen), but works in Yosemite. Or well, worked, until I switched to HDMI so I have a display that works at boot time too, sigh.
 
But speaking of annoying problems, anyone have issues with DP monitors not working on boot? I have finally given up and plugged the Asus to HDMI port (and live with 30hz) to be able to have monitor that I can actually log in on.. :p

I just got a Dell P2915Q for my Mac Pro 4,1 with Sapphire 7950 Mac Edition and can't even boot if the monitor is switched on. So, yes, your suffering is shared.

feardamhan said:
I'm seeing quite a few posts in various places about the flicker / screen blackout every few mins. Quite a few thinking its cable related, but it doesnt appear to be bandwidth based on the cable I'm using. Has anyone actually found a cable that eliminate the problem?

I've got the flickering too. Having read this thread and quite a few others, it seems likely that it's an Apple driver problem.
 
Update: I've been running apps in Full Screen mode on Yosemite based on a hunch. That hunch to click the little green button seemed to have something to it because there was a huge drop in the number of flickers. Where before it would happen every 15 minutes at least, in full screen mode it often goes for hours without a flicker.

That got me wondering whether it was anything to do with the applications I'm running rather than the monitor or driver.

Anyone else with the flicker problem tried running in full screen mode for extended periods? Could the problem be Avast or Fusion?

P.S. It's a P2715Q, not a 29. No idea how I managed to type that on the previous post.
 
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It's the driver issue. Rather than wait Apple to fix it, my permanent solution is to Hex edit the ROM's 2D profile and force the RAM frequency stay at 1250MHz.

By doing this, the card will never go into the 300/150 profile, but stay at 501/1250. The flickering only happen when the card changing it's RAM's clock speed.

I am now testing another solution, which allow the card stay at 300/1000, and able to switch up to 501/1000 when required (under 2D environment). So far so good, and this will let the card draw less power (and cooler) than 501/1250 when idle. I'd even try 300/800 and 501/800, still OK, but can't see any significant reduce on power consumption.

By running the apps in full screen, the GPU of course have to handle the screen in a little bit different way. It may reduce flickering, but won't eliminate it (I've test it on every OS update from 10.9.2 to 10.10.2 beta).
 
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It's the driver issue.

That's excellent detective work on your part. Let me know if there's anything I can do to help. I haven't used a hex editor since the 80s but it never really leaves you.

With you having confirmed that it's the driver, has anyone had a go at Apple or AMD? The Apple driver team might well be up for including a fix if they've get a decent enough explanation that it only takes them a few hours to fix and test. Also, AMD might well be cheesed-off that Apple is making them look bad.

Again, happy to help with either of those.
 
For your info.

I've tested it on every OS update, and submit a bug report via feedback assistant to Apple. I will say it's improving, but not eliminated yet. On the other hand, by contacting AMD or Sapphire, they only said it's Apple's responsibility on drivers.

In fact, in my tests, it's not too bad now (10.10.2 beta), may be only 1 or 2 flickering per day. Usually happen when switching from relatively high demanding web browser (e.g. using flash) back to desktop. I almost always run my apps in full screen, may be this is why it's improved.

It never happen under Windows (bootcamp). Therefore, it's not hardware issue.

So far, on my own computer, it only happen in 2D environment. However, as long as no 3D work, it can happen at anywhere, anytime. It means, only related to 2D profile.

I've try modify the 2D profile to 501/150 and 501/1250. Nil help, so, it's not related to the GPU clock speed change.

Once change it to 300/1250 and 501/1250. No more flickering regardless how I use my Mac.

Interestingly, for all official OSX release, fix the 2D RAM frequency to 800MHz or 1000Mhz also eliminate the problem. However, in 10.10.2 beta, it seems this still cause flickering very very occasionally. So, it seems only fix it at 1250MHz is 100% safe.

Changing the cards name, ROM revision etc won't have any effect (totally expected, but still worth to try :D).

If you have any suggestion, or want to test my ROM on your own card. Please let me know.
 
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I've tested it on every OS update, and submit a bug report via feedback assistant to Apple. I will say it's improving, but not eliminated yet. On the other hand, by contacting AMD or Sapphire, they only said it's Apple's responsibility on drivers.

I suppose the big concern has to be that the 7950 was never an Apple product so they don't have much incentive to fix the problem.

Once change it to 300/1250 and 501/1250. No more flickering regardless how I use my Mac.

Interestingly, for all official OSX release, fix the 2D RAM frequency to 800MHz or 1000Mhz also eliminate the problem. However, in 10.10.2 beta, it seems this still cause flickering very very occasionally. So, it seems only fix it at 1250MHz is 100% safe.

You said that the flicker doesn't happen in Windows, did you check the RAM clock? Is it locked in Windows? For all the fact that it's a big frame, that 150MHz should be enough to handle it. A look at the Windows clock should give the answer.

I suppose the low clock speed not being enough to drive a UHD monitor might explain why mine fails to boot in the Dell is switched on. Does your card boot in Mac mode with the monitor switched on? Mine will only start with the monitor off, the 7950 in PC mode or using HDMI.

If you have any suggestion, or want to test my ROM on your own card. Please let me know.

This machine is my main workstation so I won't do it just for giggles but if you need confirmation of a fix or extra testing, I'll be happy to help.
 
You said that the flicker doesn't happen in Windows, did you check the RAM clock? Is it locked in Windows? For all the fact that it's a big frame, that 150MHz should be enough to handle it. A look at the Windows clock should give the answer.

I suppose the low clock speed not being enough to drive a UHD monitor might explain why mine fails to boot in the Dell is switched on. Does your card boot in Mac mode with the monitor switched on? Mine will only start with the monitor off, the 7950 in PC mode or using HDMI.

This machine is my main workstation so I won't do it just for giggles but if you need confirmation of a fix or extra testing, I'll be happy to help.

Yes, I did use GPU-Z to monitor the clock speed in Windows, it will step up / down when necessary, not locked at 300/150 or 501/1250, but no flickering.

My Mac can boot with the monitor on in Mac mode (boot screen), both the 27" ACD (MDP) or my UHD TV (HDMI).

No worries, I agree that don't use your workstation for any testing purpose. Anyway, I've already test it for few months. IMO, the fixed 1250MHz is a reliable temporary work around for this problem.
 
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