updated 04:55 pm EDT, Wed October 3, 2007
iMacs suffering freezes
Widespread anecdotes, including those of MacNN's own staff, indicate that many owners of Apple's new aluminum iMacs are experiencing severe interface lockups. Multiple discussion threads in Apple's own support forums suggest that many iMacs are occasionally ceasing to accept input, despite programs and Mac OS X itself continuing to run in the background. Some users are reporting that cursors and some keyboard commands may remain functional, but that interaction is extremely limited. In all cases, the only firm solution has been a manual reboot.
Users who have spoken with Apple technical support say that the company is aware of the issue, and that the problem has been narrowed to the ATI Radeon HD cards that power the new iMacs' graphics. Despite this, only some owners are reporting more crashes with graphics-intensive programs (e.g. games), while the rest say it is random or connected to extended periods of use.
Apple did release a v1.1 update for iMacs in mid-September, but although it contains bug fixes targeted at video drivers, it does not appear to solve the problem, and may in some circumstances increase lockups or bring them on when they did not occur before. Some accounts suggest that reverting to earlier video drivers may fix the lockups; this is an unofficial solution however, and it has not been successful for all users.
Replies in Apple's forums point to some people now holding out on buying on iMac, or becoming so frustrated by the freezes that they have decided to return their computers to the store. "So I took it to Best Buy where I bought it," writes one poster. "Since I am past the 14 day return policy for them and for Apple, they or Apple are going to try and fix it."