Screen freezes for a few seconds

It how now being two weeks since I stopped using Safari, and I have not seen the issue since I made that change. I recommend anyone else try the same experiment. It seems, for me at least, to definitely be Safari related. I updated my bug report that I had filed with Apple, but I have not heard back about that.

Apple, please answer!

Same problem. Screen freezes for a few seconds while music continues in background.

I don't usually use Safari, but will wait to confirm if it's open when it happens next.

OS 10.13.6

Hardware Overview:

  Model Name: MacBook Pro

  Model Identifier: MacBookPro11,4

  Processor Name: Intel Core i7

  Processor Speed: 2.5 GHz

  Number of Processors: 1

  Total Number of Cores: 4

  L2 Cache (per Core): 256 KB

  L3 Cache: 6 MB

  Memory: 16 GB

  Boot ROM Version: 187.0.0.0.0

  SMC Version (system): 2.29f24

That may well be the case. It seems to be an issue with pre-Touch Bar MacBook Pros with Retina Displays and integrated graphics.

From my perspective, it just makes me less likely to buy a MacBook as my next laptop. My machine is already coming up on five years old, and otherwise it works perfectly for me. I also, am some one who stopped seeing the issue after I stopped using Safari regularly. I know others have reported it when not using Safari at all. It this point, that is more of an inconvenience than anything. I would prefer to use Safari because in my experience it uses the less battery than Chrome or Firefox. Firefox is my choice when I need to use a PC, but I find it is an energy hog on Mac OS.

I read that blog post and it seems like he figured out what the problem is. The bigger issue is that post is already over a year old, and Apple for whatever reason has not fixed the issue.

Also, the problem from reading through these threads is not specific to the AMDRadeonX4150. My MacBook Pro has Intel Iris Pro 1536MB for integrated graphics.

I have the same problem, console shows the exact same things!

It is highly frustrating that Apple still hasn't resolved this or even provided an answer. They probably just don't care, because only older MacBooks seem to be affacted.

I read about the Workaround of a Reboot and not opening Safari again, but it's just not satisfactory as I would like to continue using Safari.

Please Apple, get on this!

The more I read about it, the more it seems like a software issue. Does any of you doesn't have Virtualbox installed? Been doing a bit a research and some people suspect it's Vbox. I do have Virtualbox installed but not running.

I do not have VirtualBox installed. It has been about six months since I stopped using Safari as my browser, and for me that has pretty much gotten rid of the error. It just because I don't like Chrome, and Firefox kills the battery on my MacBook Pro.

If I accidentally open Safari, the freeze comes back. I need to restart my MacBook and then it goes away until I open Safari again. Other people have reported that Safari doesn't seem to be the culprit for them. I submitted a bug report back on November 14, 2018. They asked for a sysdiagnose report, which I submitted. The bug report is still open, and I haven't heard anything from them since November 27, 2018 which was basically just "thank you for submitted the sysdiagnose".

Honestly, I feel like Apple doesn't care. This seems to affect older machines at this point that they are probably just die natural unrelated deaths and then the problem will go away without them ever fixing it. Nothing I can do, I am far too invested in the Mac/Apple world to just be like, oh I will buy a Windows laptop instead.

Hi All,

Having already done the Apple Genius routine and the Bug Reporting routine without positive results I took to the @AppleSupport Twitter page. Per their adviser instructions I did the Disk Utility Repair, PRAM, SMC, and reset home folder permissions. Within 2 hours another IOAccelEventMachine2 screen freeze. I then sent them system logs also per their request.

Below in quotes is the response to my log file analysis:

"Your results came back from the escalation. After analyzing the data provided, the logs indicate that the computer is losing power. Per report from the logs it shows that the battery appears to be fully charged but the computer is shutting off and recording a no power shutdown. This behavior would be more of a hardware issue instead of software therefor the MacBook would have to be serviced at an Apple Store or Apple Authorized Retail Store."

Below is my response back to Apple Support:

"My MBP IS NOT SHUTTING DOWN. The screen is freezing for 5-10 seconds.

What exactly would the service be? 

Basically Apple's response is that the repair is my problem since I am well out of warranty. I was offered the Flat Rate Repair fee when I took my MBP to the Charleston Apple Store last year even though their diagnostics showed NO HARDWARE ISSUES with my computer. There is no expectation that the Flat Rate Repair would fix the issue as this is a deep OS/Hardware bug that Apple refuses to acknowledge. The only fair resolution would be to offer me a full $1700 credit (my full purchase price of this refurbed MBP) towards a replacement.

I appreciate your time on the phone with me gathering the details. You were extremely professional and courteous. Apple however infuriates me with their stonewalling of this issue. Again, I refer whomever reviews this correspondence to follow this thread on the Apple Forums to see that this is not a one off issue. https://discussions.apple.com/thread/8460668?answerId=250743901022&page=1

There are 10 pages of reports of the same Console Logs and identical System Freezes:

fault 19:09:13.240438 -0400 kernel virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): initial wait for 1 second expired. Continue wait for 4 seconds. stamp 49992 (gpu_stamp=49991)

fault 19:09:17.241430 -0400 kernel virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): timeout waiting for IntelAccelerator stamp 49992 (gpu_stamp=49991)

fault 19:09:17.241461 -0400 kernel void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t) - Setting restart type to 4

fault 19:09:17.241468 -0400 kernel void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t): GPURestartDequeued stampIdx=4 type=4 fromWhere=1 waitingOnIdx=4

fault 19:09:17.241538 -0400 kernel void IOAccelEventMachine2::restart_channel(): GPURestartSkipped stampIdx=4 type=4

fault 19:09:17.241543 -0400 kernel void IOAccelEventMachine2::restart_channel(): no channel associated with stamp_idx 4 (type 4)

Please Apple, acknowledge and work with your customers to resolve this issue!

Thank you again for your assistance"

Unfortunately the stonewalling, delay, and disregard tactics continue. I'll let you know if I hear anything back.

I see the latest OS update contains fixes for Intel Graphics Driver and IOAccelerator, although nothing related to the system freezing. At least the code hasn't been abandoned though, so maybe this will get fixed one day. Is anyone seeing the problem on 10.14.5?

Only MBPs have that...

The main goal of Apple's automatic graphics switching is to balance graphics performance with long battery life. Intel's latest stable of mobile processors—Core i3, i5, and i7—all include integrated graphics in the same package as the CPU. Dubbed Intel HD, this integrated graphics processor is designed primarily for efficiency. While its performance is far better than the previous GMA950, for instance, it still wouldn't be classified as good for "performance" graphics in any sense of the term in common usage.

In previous MacBook Pros, Apple attempted to achieve this goal by including a discrete GPU along with the integrated graphics from NVIDIA's 9400M chipset. Users could switch from one to the other manually via System Preferences, which required user intervention as well as the annoyance of logging out and logging back in. So, you could have either performance or better battery life, as long as you were willing to interrupt your workflow.

https://arstechnica.com/gadgets/2010/04/inside-apples-automatic-gpu-switching/

Hello GamerSan. The ONLY fix so far is to revert to MacOS 10.12.6 Sierra. I have tried every iteration of MacOS from 10.13 to 10.15 betas and the "virtual IOReturn IOAccelEventMachine2" has occurred on every one of them. All were clean installs and within 2-3 hours to 2-3 days the "virtual IOReturn IOAccelEventMachine2" error would occur. I installed 10.12.6 21 days ago and no screen hangs or errors since. I don't like that I have been "limited" to the older MacOS, but I am happy not to have the freezes anymore.

I wonder if we'd get more traction if everyone with the affected hardware configuration chipped in for a full page ad in the New York Times saying that Apple caused this problem with the introduction of High Sierra (10.13), knows it exists for everyone who bought a certain generation of their computers, and has refused to replace the hardware or mitigate the problem.

Even after several people provided a detailed description, there is now useful help from Apple?

Hi pjkelnhofer,

Is your Mojave clean install still "IOAccelEventMachine2::waitForStamp" error free?

Thanks