OS/X Sierra – External Display Issues

      13 Comments on OS/X Sierra – External Display Issues

If you’ve not yet updated to OS/X Sierra you may want to wait for the 0.1 release.

Many users experience no issues when upgrading but more than a few are finding they need to do some fairly drastic things to get their system working as normal. There are numerous reports of people doing a simple SMC Reset (hold down Ctrl + Shift + Option and press power) to get things back to normal. Others are having to perform full “clean installs” of Sierra to get things back to normal.

Sierra OS/X Issues

In a brief search for OS/X Sierra problems there seems to be numerous issues related to two critical areas of the operating system: Display Management and Thunderbolt I/O.

Users Report Loss of HiDPI Scaling

Top OS/X Sierra Problems

Troubleshooting OS/X Sierra Problems

Dual Thunderbolt External Monitors

Personally I am having an issue working its way through Apple Support related to the use of dual Thunderbolt-port connected external displays.    Whenever I connect and turn on two monitors, one connected to each TB port, the FAN 0 speed slowly cranks up to 6,000 RPM (full throttle).    Depending on whether or not I’ve recited the proper black-magic incantations I may-or-may-not be able to turn off one of the two displays and make the fan quickly ramp back down to a normal 2500 RPM.    It is interesting to have my external HP monitor button act as though it is wired directly to FAN 0 but that 6,000 RPM fan noise is irritating after about 3.5 seconds.

istats_2016-10-17_11-44-05

Apparently there are times when I’ve used the wrong tone or maybe mispronounced an ancient Egyptian God’s name and the simple monitor on/off trick doesn’t work.   The system will completely hand and deprive me of the use of my keyboard or mouse after I turn off a monitor; Even after disconnecting all peripherals and opening the laptop to use the track pad on on-board keyboard.

I’ve been using the same hardware, same connections, and same applications for 2 years now (other that a myriad of software upgrades).    The only thing that has changed since the “fans working normally” days of last week and the 6,000 RPM mode is having upgraded to OS/X Sierra earlier this week.      My guess is someone at Apple buggered a register in the TB I/O code and has overflowed some bits to piss all over other elements of the OS.   We’ll see if Sierra *.1 fixes the issue.  I can only hope it does.

Looks like my MacBook is at it again – time to sign off… and good luck!

istats_power_tb_still_on_2016-10-18_17-01-16

 

Update: October 19th 2016

What I’ve Learned About The Display Problem

The issue I am having with fan 0 hitting full throttle seems to be related to running both TB ports.  For the sake of discussion I am calling the port nearest the power input TB0 and the port closest to the USB input TB1.

TB0 = black, TB1 = white

TB0 = black, TB1 = white

The problem appears to triggered by TB0 , but it does require the help of TB1.

Case 1: Reproduction

Plugin HP ZR2440w monitors into TB0 and TB1 using display port.

Make sure TB1 is the primary display.

Start firing up apps.   Firefox,Terminal,iMessage,iTunes,Siri,Snagit,Slack in my case then start Photos and the fan quickly ramps up.

Turn off the monitor connected to TB0.   The ran immediately starts to ramp down.

Case 2: Add HDMI

Running similar scenarios with the HDMI port pushing video to a third HP ZR2440w seems to have no affect.    Whether it is connected or not the results are the same as above when TB0 and TB1 are active.  Turn off TB0 and the fans ramp down.  Turn on TB0 and the fans ramp back up.

Case 3: Drop TB1

An interesting test case, making TB0 the primary monitor and doing the same exact scenarios above and turning TB1 on/off has no impact on the fan RPM.   Once the fan is at 6K RPM it stays that way even though the system clearly shows the TB1 display being dropped from the display stack.

osx_sierra_dual_monitors_2016-10-19_11-22-32

Case 4: TB0 As Primary , Off or Discconnect

This one makes perfect sense when you think about it for a moment; though I do believe OS/X needs to address this as a separate issue.     If you make TB0 the primary monitor it will NEVER drop from the display stack.   If you turn it off OS/X does not make another display the primary display, keeping the TB0 monitor “in memory”.    Same thing if you physically disconnect the TB0 cable.  It will NEVER drop.

Because of this turning off or physically disconnecting TB0 while the fan is pegged at 6KRPM has not affect.

If you make TB1 the primary display at this point, OS/X will immediately drop TB0 from the display stack and the fan RPM starts to drop.

Update: October 19th 2016

It Is Siri

Of course it is.  The biggest change to OS/X Sierra is the addition of Siri.

Through an errant keyboard click I happened to engage Siri and IMMEDIATELY the fan speed dropped from 6K RPM to a normal 2K RPM.     As soon as Siri stopped listening the fan went back to full throttle.

Now that is odd.    Repeated tests, same results.

Siri code is toggling SMC registers.  Sounds like a buffer overrun to me.

Maybe It’s Not Siri

Turns out that Siri turns off the fans in order to better hear the listener.   It seems like Siri is only doing something to force the fan speed to 0 and is not directly related to the issue.   An a related note, some gamers have fried their MacBooks because of this by enabling Siri and then getting it stuck that way while running a game.  Poof… overheated MacBook.  But that’s another issue.  No word if the MacBook was completely fried or not but I’m guessing it shut down before that happened.

It’s Back

After the Sierra 10.12.1 patch turning on Siri doesn’t prevent the problem like it had previously.   Whenever DP0 + DP1 + HDMI are connected the fan is at 6K RPM.   DP0 + DP1 it hovers around 5k RPM.    DP0 + HDMI seems better (not great).    Turn OFF DP0 and DP1 and the fan almost immediately goes 2K or less RPM.

Weeeee!

Maybe Apple support will call me back.   It’s been a month with no updates.

OSX Left Fan (Fan 0) behavior with external monitors in place.

OSX Left Fan (Fan 0) behavior with external monitors in place.

Back To El Capitan

Apparently after the initial interest in the problem, Apple decided they couldn’t be bothered with this.     Sierra constantly runs the left fan at 5K+ RPM any time the HDMI monitor is attached.   I never get a call back from Apple Support when I leave messages these days.

I reverted to El Capitan.    Under peak load the left fan is maxing out at less than 4K RPM with all 3 monitors going.   Not an apps issue, at least not without “assistance” from macOS Sierra and not a hardware issue.

Proper Fan Speed on El Capitan

Proper Fan Speed on El Capitan

Apple, you’ve finally failed me on the same level as Microsoft.     Boo.        I’ll take the 3 hours of downtime in 2 years over countless hours lost to Windows over the same period.  Still sucks having gone from 5 minutes of downtime in 2 years to 3 hours and 5 minutes because I had to revert my entire system to a 45-day old backup running El Capitan.   That HUGELY SUCKS.

Lesson learned:  ignore the future macOS updates from Apple.   Since Steve Jobs has gone on to better things Apple has slowly been working its way to mediocrity.

13 thoughts on “OS/X Sierra – External Display Issues

  1. Lukas

    Exactly the same here. As soon as I start Siri the fans stop spinning! But it also slows down when removing the external monitor, that however takes much longer to slow down. How did you sort it out? Disabled Siri?

    Reply
    1. lcleveland Post author

      I had to disable Siri.

      Apple opened a ticket & called a couple of times; even had a download of my system sent to them but haven’t heard a thing since.

      Reply
  2. Lukas

    I tried to disable Siri but still no luck. As you say the fans stop spinning when you trigger Siri to listen. Have you ever solved the issue? My fans are going crazy and I with them!

    Reply
    1. Lukas

      I did that and even reset the SMC and PRAM, to no avail. It is still pretty high. Only removing the external monitor helps though it does take a while to slow down. Thanks for your help though.

      Reply
  3. Lukas

    Hi Lance,

    I’ve just installed 10.12.2 and it seems to have improved the fan spinning but only partially. It revs up randomly. Pulling the HDMI out and re-connecting it calms the fans down. I’ve really given up on this. I spend my days working without the external monitor just to keep the noise down.

    Apple support called me and after a long hour of NOTHING and usual SMC and NVRAM resets nothing was sorted. “An upcoming update could fix it but it all depends on whether the developers decide to fix it”

    I’ll keep you posted if I spot anything new.

    Reply
    1. lcleveland Post author

      I went through the same thing with Apple Support. After they couldn’t solve the issue they just dropped it. I can’t get any kind of response on the case I had open with them.

      I’m glad things are a little better with Sierra. I spent a FULL DAY restoring a 60-day-old OS/X El Capitan version of my system. It took a long time to get everything back that happened during that 60 day span on top of the OS. The fan RPM was better. But… version 10.11.6 of El Capitan is now doing the same exact thing.

      I also noticed , thanks to iStat Menus (thinking I’ll pay the $15 for this tool), that there is some correlation between internal temps and the fan speed. With HDMI plugged in an NO APPS running (besides iStats and the normal system stuff) that the #1 temp rise is in the GeForce GPU Die – Digital. Within 2 minutes of connecting the HDMI display and even just 1 TB display the die temp rises jumps from 149 to 167 Celcius . That’s a 12% rise in 2 minutes. The other temps are all physical proximity issues I’m guessing (Left Fin Stack 126 to 144, CPU Analog 140 to 157, CPU Core 1 and 2 up 15, and CPU System Agent Cor up 15). At least that makes sense.

      Whatever Apple did in Sierra and the latest El Capitan release has basically rendered the HDMI port useless on a MacBook Pro Retina.

      They likely won’t put any resources into fixing this as it is just one more thing “legacy” MacBook users will have to annoy them and push them toward buying the crazy-overpriced-for-what-you-get 2016 model. 😞

      Reply
  4. pecharLukas

    It’s a good tool though I stopped using it. I spent lots of time looking at temperatures and less time working 🙂

    Lately it seems much better when using the external monitor but still not a 100%. I guess we’ll never know.

    Reply
  5. Varun Yellina

    I’ve had the same issues. I’m using only a single external monitor DELL U2715H via mDP-DP or HDMI-HDMI. In addition to constant maxing out of fans, the CPU usage spikes to a crawling 600%. The kernel_task ramps up usage to prevent damage(actual temp 56deg). Only when I disconnect the external monitor does the CPU usage return to normal. The maxed out fans is 100% of the time. Extreme CPU usage is triggered by playing video/audio on Chrome/Safari or using a design application like Sketch.

    Apple Service has already replaced my motherboard(rMBP 2015 Dual Graphics). The issue still persists. Before this issue cropped up a couple of months ago on macOS Sierra, everything was fine for about 10months of using the same hardware config.

    Reply
  6. Sebastien

    Exact same problem here. Performance drops are huge when connecting external screen. Fans getting high too. Siri listening stops the problem.

    Reply
  7. Brian Sanchez

    Exact issue here. I avoided upgrading to Sierra for months to avoid issue like this. I finally succombed to installing 10.12.5, and I’m furious something this basic has yet to be addressed. Apple Support has no clue. I pleaded with the tech to add it as a known issue, which they said they did.

    Mulling over downgrading to El Capitan. Apple quality for macOS has gone to shit. I will NOT be upgrading back unless I can find evidence online that they fixed this issue.

    Reply

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