Screen freezes for a few seconds

I'm getting the same error Mid 2015 Macbook pro... Happens when using safari

virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): initial wait for 1 second expired. Continue wait for 4 seconds. stamp 2620847 (gpu_stamp=2620846)

virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): timeout waiting for IntelAccelerator stamp 2620847 (gpu_stamp=2620846)

void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t) - Setting restart type to 4

The duplicate is probably to the bug report that I did months ago. They asked me a couple follow-ups after I first reported it, but I haven't heard anything since. Every time that Mac OS gets an update, I read to see if anything sounds like they are addressing the issue. Like everyone else, I am losing my faith in Apple since they seem to have no interest in fixing this despite plenty of people reporting it. It is clear the Mac is not an important part of their business model anymore.

Someone debugged and traced the issue to code in the graphics driver (linked from this thread somewhere). I guess then it's specific to a particular GPU or family. Even if it's affecting only older Macs with specific hardware, you'd think for a trillion dollar company, Apple would be able to dedicate some resources to providing a fix.

Just so I could say I have tried every possible fix I changed out the thermal paste on my 2015 MBP. Unfortunately within an hour of rebooting the Console was showing IOAccelEventMachine2 errors again. At least the inside of my MBP is now cleaner than before! Sorry, thermal paste is not a fix for IOAccelEventMachine2 errors.

I've been hoping for an answer for a long time on this, too.

I can add this. Some of the answers here say that it is related to Safari. I do find that it happens much more when I am using Safari, but it sometimes happens to me when I am not running Safari (unless it is running in some process in the background somehow not visible to the UI). I avoid using Safari because of this problem. I am using Chrome and Opera instead most of the time.

For me, the primary identifiable characteristic of this problem is "time freezes". That is, the time display at the upper right corner of the screen, which includes seconds for me, stops running. Then suddenly it starts running again, skipping ahead typically 90 seconds or more.

It seemed to me this all started after one particular software update. Unfortunately, I couldn't tell you which one. But perhaps a correlation of incident dates and software updates would point to a particular update. Also, I wonder who has the problem who is still running on an old software release for whatever reason. I'd guess there is a threshold release and those before it never have the problem.

My last "freezelette" was literally just moments before downloading 10.14.5 two days ago. I can report no episodes since the update but don't take that as anything other than reporting in. This is a scurrilous bug that thus far revels in leading one down the path of false hope. As Yogi Bera once said, "When the day comes you don't remember this thing anymore, that's the day you can celebrate it's over."

Unfortunately I am 10.14.5 and I still get the screen freeze and "IOAccelEventMachine2" errors. I feel stuck because a future updated Mac OS "may" fix the issue and according to https://www.apple.com/shop/trade-in my MBP doesn't even qualify for a store credit, only recycle value. I really don't want to give up this model with the mag-safe, USB ports, and SD Card slot all built in. I'm glad to hear that hmorneau received a non "IOAccelEventMachine2" error machine on eBay, but that seems like a risky proposition to me.

Hi all,

Just wanted to report that the issue is back for me. So even after switching computer, the issue is back. So now I'm starting to think that's not an hardware problem but a software one.

Anybody have tried the newest macOS in beta to see if the issue is resolved? Hopefully the next update will fix the issue.

Sorry to hear that hmorneau, but glad to have you back. The place wasn't the same without you.

Friends, I must be the only one who has not experienced a single episode since installing Ten 14 Five....almost two weeks ago. Here's my config

Macbook Pro ( Retina, 13-inch, Late 2013)

2.5 GHz Intel Core i5

8 GB 1600 Mhz DDR3

Inte ; Iris 1536 MB

500 GB SSD SM0512F

5 cycle count on fairly new battery

Tacos Last Night

Background Noise Stream: Either NPR or Joe Rogan Podcast

Add me to the list. (purchased fall of 2016) mid 2015 Macbook Pro, 16GB, 500GB SSD. Not sure why but I have put up with this for at least a year and after 4 or 5 clean installs with nothing else installed just to see if it comes back, it always does. Same error messages from the console. Luckily this is my work laptop and we bought the 3 yr support. I can't take it anymore as it freezes a dozen times or more per day. Taking it to the Genius Bar next week.

Here's an update from me. I'm still not sure that my situation is exactly the same, since my "time freezes" can last for 90 seconds or more, though they are sometimes followed by a second, shorter occurrence as described by others here.

I often get Current Status Bar IOSurafce port is invalid. (Note the misspelling.)

I did try turning off "Automatics Graphics Switching" in System Preferences. It had no noticeable effect on how often the problem occurs.

It does seem to happen significantly less often when I avoid Safari, but still happens. That could mean Safari is not the cause, but it does something that encourages the problem.

That doesn't seem to be a setting in my Energy Saver panel of System Preferences.

gplewis wrote:

Hey have you tried turning 'automatic graphics switching' off in the energy panel of settings? The thinking being it will force use of the GPU rather than the integrated intel graphics chip and hopefully stop the kernel fault.

I installed the Catalina beta a few days ago and went for about 2-3 days without an IOAccelEventMachine2 error. Then like clockwork I got my screen freeze and the same string of IOAccelEventMachine2 errors in the Console app. I'm perplexed that this error doesn't seem to occur for 2-3 days after a clean install. I'm annoyed that it occurs at all!!!

I'm currently on macOS 10.14.6 beta 3 (build 18G59b). The first 2-3 days have been freeze free. I then got the 5 second freeze 10 minutes from each other last night. I created a sysdiagnose for both of them and sent it to Apple via Feedback Assistant. A third freeze happened again today. Sending a sysdiagnose again. Haven't heard back from them since the last time asking for an updated sysdiagnose. It's sad to hear Catalina is experiencing the same problem. I've experienced this in macOS 10.13 High Sierra, macOS 10.14 Mojave, and was hoping it would at least be fixed by macOS 10.15 Catalina.