Level 1

10 points

Sound stuttering after Mountain Lion install

Dear community,

after having installed OSX Mountain Lion my sound startet stuttering whenever there is rapid movement on my screen.

This includes e.g. window movement, scrolling through image loaded websites or video playback (flash player, quicktime).

A restart didn't help. I'm using stereo output, not digital.

I have connected a second monitor but the problem persists after disconnecting it. Movement on the second monitor also causes the sound to stutter.

My GPU Diode temperature is at 85°C (there is some bug that keeps the GPU under load while a second monitor is connected AFAIK), but I guess it was the same under Snow Leopard.

In Snow Leopard the sound output was always perfect even under heavy load or heavy HDD I/O.

Any ideas?

iMac (27-inch Mid 2011), OS X Mountain Lion

Posted on Jul 28, 2012 5:48 AM

1,223 replies

Sep 24, 2012 5:45 AM in response to FrederikY

Yes definatly contact applecare. the more that do, the better for everyone. I suggest that if you can, make an open mic recording of the issue first (use the voice memo function) and then you can tell them you have a sample to send them. There isnt actually a sound card that can be exchanged, it would be the whole logic board.

I spoke to a guy called Lukas and he passed my recording onto the engineers.

Use this link (I think your in Germany) and select Erste Schrittehttp://www.apple.com/de/support/contact/

mfg

Victor

Sep 24, 2012 5:49 AM in response to Victor In Munich

OK, thanks I'll try that.

Sep 24, 2012 6:19 AM in response to tttxx

I talked to Apple care now, sent him this video (I think the video is representative): http://www.youtube.com/watch?v=6Sm9fkx-hTk

…and he will call back after he watched the video

Sep 24, 2012 6:42 AM in response to FrederikY

Result: He will send me a diagnostic tool which loggs the whole system while I reproduce the sound stuttering: For the engeneers to decide if this is a hardware problem or a software problem (we know the answer).

LouFace

Level 1

9 points

Sep 24, 2012 7:10 AM in response to FrederikY

It infuriates me the way they try to dance around the fact that it's their new software that has ballsed everything up. All our different model/age/type of computers just happened to aquire the same problem at completely different times, where installing Mountain Lion was just a coincidence?

tttxx Author

Level 1

10 points

Sep 24, 2012 7:37 AM in response to LouFace

After a few days using 10.8.2 I can't reproduce the problem anymore.

With 10.8.0 I had the stuttering whenever I just scrolled through websites with Safari. The GPU diode temp was at 85°C all the time.

After the 10.8.1 update the issues still occured when for example watching a clip from myspass.de and listening to iTunes music at the same time. It was much less frequently though and difficult to reproduce.

Since the last update I haven't had this issue anymore and the GPU diode temp is below 65°C in idle mode. Even when playing Diablo3 for some minutes the mouse lags don't occur anymore and the music plays 100%. And one can definitely tell the difference between a game lag (10.7) and a mouse input lag/glitch (<=10.8.1).

So what has changed? Was ist a gfx driver issue and the freezes were a consequence of gpu throttling due to high temperatures?

Can anyone share a way to reproduce the problem with 10.8.2 on a stock iMac with internet access?

Sep 24, 2012 8:51 AM in response to tttxx

Glad 10.8.2 solved you issues. For me it didn't.

How to reproduce? Boot computer to mountain lion. A fresh install will do. Play any media. iTunes QuickTime Internet radio online games. Sound will break up anytime between 1 minute and 3 hours later.

tttxx Author

Level 1

10 points

Sep 24, 2012 8:57 AM in response to Victor In Munich

Could you check your GPU temperature when this happens? I used iStat for the dashboard to get the numbers...

Does the coreaudiod process jump to 10% CPU usage? (filter to "All processes" in the activity monitor)

I'm still interested because I don't trust the silence yet.

Sep 24, 2012 9:30 AM in response to tttxx

My iMac became a lot cooler after 10.8.2, too.

But the stuttering still exists 😟

LouFace

Level 1

9 points

Sep 24, 2012 9:44 AM in response to tttxx

Upgrading to 10.8.2 is what caused my stuttering 😟

Sep 24, 2012 10:01 AM in response to LouFace

Reinstall Mountain Lion, and don't install the update!

LouFace

Level 1

9 points

Sep 24, 2012 10:10 AM in response to FrederikY

Update? I only have the 10.8.2 Mountian Lion. I installed it directly from the Apple website. Went from Snow Leapord to Mountain Lion 10.8.2.

Sep 24, 2012 10:29 AM in response to LouFace

ok, I see. I thought you had 10.8.0 without problems…and then installed the 10.8.2 update.

Put so you'll probably have the same stuttering in 10.8.0.

Jazzman

Level 2

169 points

Sep 25, 2012 6:39 AM in response to FrederikY

I've found the same thing. 10.8.2 did me in. I'm calling the Apple Care line today. I don't know if they have a fix yet or not, but I want to log my issue. I've got a late 2010 27" iMac. Listening to music via a high end headphone system is pure agony with this stuttering and occasional crackle sound. This happens with an AIFF (external HD) library as well as an ACC library (stock Apple internal HD). It even happens when I stream music via MOG.

I'm going to have to go back to CD's via a CD player until this gets fixed.

Analooog

Level 1

0 points

Sep 25, 2012 12:37 PM in response to tttxx

Here: http://reviews.cnet.com/8301-13727_7-57489874-263/sound-stuttering-after-mountai n-lion-installation/
it is noted already on 9th August. It's sad that it has been published so many times and Apple not taking any action yet after 2 updates! What a pity.

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Sound stuttering after Mountain Lion install