MacRumors is reporting on a discussion that is on fire with reports of a downgrade in SATA speeds for the new 13″ MacBook Pro, and the 15″ models as well. Apparently, System Profiler is now reporting a SATA speed of 1.5 gigabits, down from 3 gigabits on the new machines.
While this change will not matter to anyone with a mechanical hard drive, or a low-end SSD, those using high-end SSDs like the Intel X-25M could see a performance decline. MacRumors forum member Shao was the first to post benchmarks from a 13″ unibody MacBook and a 13″ MacBook Pro, and the results are startling.
The theoretical maximum for throughput is effectively halved in machines with identical chipsets, the NVIDIA MCP79 AHCI. While one could argue that theoretical maximums and the real world seldom overlap, in at least some instances, like audio and video work, there might be performance degradation.
Exactly why Apple is doing this, or even what exactly has been done, is only speculation at this point. 1.5 Gbit/s is the specification for SATA I, while 3.0 Gbit/s is SATA II, so the question then becomes whether Apple has downgraded to a previous standard. If the 15″ MacBook Pros turn out to have been downgraded too, one could argue it was just one of many changes made to increase battery life. If some models aren’t throttled, an argument could be made for Apple segmenting its lineup, as it does with discrete vs. integrated graphics. However, the difference here is that the 13″ unibody MacBook already had SATA II. Further, the current white MacBooks apparently still have SATA II, at least according to those posting specs from Apple Stores today.
One thing is certain — the future is fast SSD drives like the Intel X-25M. Those considering a long-term purchase of a MacBook Pro, with the intent of upgrading to an SSD in the future, would do well to wait until more is known. As for those like myself who own unibody MacBooks bought before last week, this news puts a little salve on the burn of being without FireWire.