A recent Apple firmware update is causing major problems for some MacBook Pro owners, talk on Apple's support forums indicates. The update was intended to bring full 3Gbps throughput to the Pro's SATA controller, after it was discovered that the newest models had been artificially limited to 1.5Gbps. While the cap does not affect conventional hard drives, some SSDs cannot operate at peak speeds without the higher threshold.

Pro owners report that if installing the new firmware on a system with upgraded or otherwise non-standard storage, drives may work only intermittently, if at all. The only solution may be to reinstall the default hard drive supplied with a computer; Apple has not produced a means of rolling back the firmware update, and it is not handling support for aftermarket parts. Genius Bar technicians say they are also unable to restore a controller to its original state.