Critical OS X Bug Threatens To Undermine Apple’s Reputation

A severe and unresolved bug in Apple’s well known OS X operating system could threaten to undermine its reputation which has taken years to build.

Users of OS X, especially the latest version, Lion (10.7.x) have been experiencing periodic (and sometimes very frequent) “black screens of death”, similar to Windows BSOD (Blue Screen Of Death).  The issue currently appears to be affecting all MacBook Pros produced between 2010 and 2012, however problems have been reported in MacBook Pros as early as the 2008 models.  Also, the issue appears to be predominantly affecting users of the latest version, Lion, however issues have been reported from users running OS X versions from 10.4 onwards.

The cause of the issue initially seems to be a mystery, with the only link between users accounts being that it is when they are performing similar actions it crashes time and time again.  Apple have acknowledged the problems that some users have been experiencing, however there has failed to be any admission that it is an OS X bug or when the issue might be resolved.

When the black screen of death occurs, the only option for the user is to turn off the MacBook using the power button and reboot.  Some users have reported that rather than the black screen of death, they see the standard kernel panic message.  However, the black screen of death has been reported by the vast majority of people.

Having analysed reports from several sources, we have concluded (along with other people) as to the probable source of the crashes.

Most of the crashes have one thing in common, and that is the graphics cards and more specifically the dynamic switching between the integrated and discrete graphics cards.  By analysing the kernel panic logs, they almost always indicate the graphics cards and related processes as being involved in the kernel panic.

Although denied by Apple, the source of the issue seems to be at a very low level, either with OS X and / or with the hardware.  Apple have stated to most users who have sought help that the issue lies with third party hardware or software, but reports from users would appear to suggest that this is incorrect.

Another common theme seems to be with MacBook Pros with an Intel based onboard graphics card with a supplementary Nvidea graphics card.

The only solution that partially (of sometimes completely) resolves the issue is to disable the dynamic switching between the integrated and discrete graphics cards.  Although some of these options can be tweaked in the OS X system preferences, dynamic switching cannot be disabled completely.  However, by using the freeware application gfxCardStatus users can disable dynamic switching in most cases.  It is recommended to select the “Integrated Only” option which, in the vast majority of situations, will stop dynamic switching of the graphics card.  It has however been reported that when a MacBook Pro wakes up from sleeping that the dynamic switching occurs even with gfxCardStatus set to integrated only.  It is, therefore, recommended that if using gfxCardStatus on its “Integrated Only” setting hasn’t completely stopped the crashes that you also prevent your MacBook Pro from sleeping using the energy savings preferences.

With the problem occurring, most likely due to a fundamental low level issue with OS X or common hardware used in the MacBook Pro there is little chance of avoiding the dreaded black screen of death without disabling dynamic switching between the graphics cards.  The black screen of death can be caused by something as simple as switching between windows, which is a hard thing to avoid!

MacBook Pros sent away to Apple under the AppleCare package have been formatted and had a fresh OS X install, on which they have reported to the users that they cannot recreate the issue, however, most users report another black screen of death within a short period of time after receiving their computer back.

The issue threatens to undermine the long standing good reputation of Apple, and its persistent denial of the problem only serves to make MacBook Pro users frustrated, annoyed and angry.

Have you experienced the black screen of death?  Has the temporary fix worked for you?  Feel free to comment below.

Image: h_okumura