Apple has released a firmware update that fixes the issue where the latest MacBook Pro reports SATA 3Gbps as 1.5 Gbps. As you may have seen with our news, the June 2009 MacBook Pro was shown to report SATA transfer rate as 1.5 Gbps instead of the faster 3.0 Gbps. For most users, the speed is not going to be a major issue as mechanical hard drives have yet to saturate even the 1.5 Gbps. However for SSD users, this can be some performance hits with the 1.5 Gbps. Luckily, Apple is quick to action and release the 3.35 MB firmware update that addresses such issue. It is still yet unknown whether this is just a fix that allows the MacBook Pro to report 3.0 Gbps or actually address the physical transfer rate.

Source: Apple