Apple may have been aware for some time of the problem of new MacBook Pros crashing under heavy loads. According to the UK’s PC Pro magazine, Apple appears to have deliberately turned off Turbo Boost for the top-end model, with a dual-core 2.7GHz Intel Core i7-2620M processor, when running Windows under Boot Camp.
The magazine originally thought that Turbo Boost had been disabled under OS X as well, but then tests by AnandTech showed that it was only disabled under Windows. “We first noticed a problem when the benchmarks finished five full runs and the results popped up on screen: the times taken to complete several of the most intensive tests were rising with each run” says PC Pro. “This would suggest an overheating problem, so we ran a temperature monitor to find out how hot this Sandy Bridge CPU was getting.”
In fact the CPU was reaching around 93°C — almost 200°F. “93°C is not necessarily too high for a modern CPU, but it is the root cause of the bigger performance problem.” PC Pro says they’re sure the processor isn’t turning off Turbo Boost dynamically, since it didn’t work at all during their week of testing no matter what the CPU temperature was. Also, the cheaper model with the i5 processor did use Turbo Boost, as did the i7 model under OS X.
And after measuring the underside temperature of the top-end model at 60°C — 140°F — they conclude that it might actually be a better deal to buy the cheaper 13-inch MacBook Pro. If Turbo Boost is disabled on the higher model, the lower-end version will actually run Windows faster than the more expensive MacBook Pro.