Screen freezes for a few seconds

Same problem here, it happens multiple times a day.

Console report from a few days ago:

My device:

Modelo: MacBook Pro

Identificador de modelo: MacBookPro11,4

Nome do processador: Intel Core i7

Velocidade do processador: 2,2 GHz

Número de processadores: 1

Número total de núcleos: 4

Cache L2 (por núcleo): 256 KB

Cache L3: 6 MB

Memória: 16 GB

Versão da ROM de arranque: MBP114.0184.B00

Dear Apple,

Please assist in resolving the ongoing "virtual IOReturn IOAccelEventMachine2/void IOAccelEventMachine2" issue. There are 2-3 years and multiple user reports on this issue and not a single helpful response from corporate. This is not an isolated issue and there are exact and repeated Console output messages for your team to examine. This issue is so frustrating because there is no pattern to its occurrence. There is no sequence of user events/inputs that seem to trigger this issue. There is no specific application running that seems to trigger this issue. There is no timeframe that seems to trigger this issue.

There does appear to be a hardware configuration most at risk:

Here is the Console output for reference:

Model Name: M

There are multiple users with the same issue and you are welcome to contact me directly for further input.

Thank you

Hello NachbarsKatze,

I get the same errors, will you say please, did you find a solution to this problem?

Thank you!

2:42PM

* virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): initial wait for 1 second expired. Continue wait for 4 seconds. stamp 141114 (gpu_stamp=141113)

* virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): timeout waiting for IntelAccelerator stamp 141114 (gpu_stamp=141113)

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

* void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t): GPURestartDequeued stampIdx=4 type=4 fromWhere=1 waitingOnIdx=4

* void IOAccelEventMachine2::restart_channel(): GPURestartSkipped stampIdx=4 type=4

* void IOAccelEventMachine2::restart_channel(): no channel associated with stamp_idx 4 (type 4)

2:45PM

* Trying to grab power assertion while we already have one

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

* void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t): GPURestartDequeued stampIdx=4 type=4 fromWhere=1 waitingOnIdx=4

* void IOAccelEventMachine2::restart_channel(): GPURestartSkipped stampIdx=4 type=4

* void IOAccelEventMachine2::restart_channel(): no channel associated with stamp_idx 4 (type 4)

2:55PM

* virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): timeout waiting for IntelAccelerator stamp 155547 (gpu_stamp=155546)

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

* void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t): GPURestartDequeued stampIdx=4 type=4 fromWhere=1 waitingOnIdx=4

* void IOAccelEventMachine2::restart_channel(): GPURestartSkipped stampIdx=4 type=4

* void IOAccelEventMachine2::restart_channel(): no channel associated with stamp_idx 4 (type 4)

3:00PM

* virtual IOReturn IOAccelEventMachine2::waitForStamp(int32_t, stamp_t, stamp_t *): timeout waiting for IntelAccelerator stamp 162748 (gpu_stamp=162747)

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

* void IOAccelEventMachine2::handleFinishChannelRestart(IOReturn, int32_t, uint32_t): GPURestartDequeued stampIdx=4 type=4 fromWhere=1 waitingOnIdx=4

* void IOAccelEventMachine2::restart_channel(): GPURestartSkipped stampIdx=4 type=4

* void IOAccelEventMachine2::restart_channel(): no channel associated with stamp_idx 4 (type 4)

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.

I just started having this problem, (summer 2019) on my MacBookPro 15" [2015] with Retina display & Intel Iris Pro / same setup as noted repeatedly above. But this has been only with Mojave (now 10.14.6).

Same GPU error as everyone else :(

BDAqua wrote:

or maybe it's a bug in APFS...

I can confirm that it is not due to APFS.

I bought my MacBook Pro Mid 2015 recently from a refurbisher. It came with 10.13 High Sierra installed on the SSD formatted as HFS+, not APFS.

I'm also seeing the same behavior. I'm also seeing similar items in my console.app whenever the system hangs

I recently got the 2018 15" i7 MacBook Pro. It has worked without any hitches for the last couple of weeks. Today while browsing in Chome the screen froze in a kind of multicoloured zig-zag pattern. There was no key or mouse response so I had to reboot from the boot button. Everything looks normal again. That's all I can report (I'm not tech savvy) but I'm now apprehensive for the next "incident".

NachbarsKatzeThanks - I was concerned it might be a hardware issue. And, yes, all the 15" models have dedicated GPUs. Trouble is if this problem is intermittent it is impossible to demonstrate and get a replacement (it is beyond the 14-day return policy). If I had been thinking straight at the time I should have just taken a photo of the screen as evidence. I'll do that if it happens again. All my Final Cut Pro video stuff (that's all I basically do on this machine) I keep on external drives, so no concern about data loss if this thing goes belly-up.