Apple released a Firmware update aiming to fix the issue faced by the owners of the new MacBook Pro models, limiting the transfer speed of the sata interface to 1.5 Gb/s inteaded of 3 Gb/s.
MacBook Pro EFI Firmware Update 1.7 addresses an issue using drives based on the SATA 3Gbps specification with the MacBook Pro introduced in June 2009. This update allows drives to use transfer rates greater than 1.5Gbps, however Apple has not qualified or offered these drives for Mac portable computers, and their use remains unsupported. All previous and current Apple portables with a SATA drive interface include a SATA 1.5Gbps hard drive.
Direct link to the download support webpage: http://support.apple.com/downloads/MacBook_Pro_EFI_Firmware_Update_1_7_
