It's apple that use their own firmware, if you put in the same drive purchased directly from the manufacturer then you will get SATA II. Just do that if you absolutely need SATA II. It's cheaper that way and you get a better warranty.
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Apple Does it again SATA 1.5 in a 2010 i7 MBP 15!
- Thread starter magbarn
- Start date
- Sort by reaction score
It's apple that use their own firmware, if you put in the same drive purchased directly from the manufacturer then you will get SATA II. Just do that if you absolutely need SATA II. It's cheaper that way and you get a better warranty.
A better question is, what are the performance differences between the two, 1.5 vs 3.0. Higher = better, but where are the numbers to back it up.
sure, but why do it in the first place? There must be a benefit to it, otherwise they wouldn't do it.
I think your getting hung up on the logic of this argument. Specifically that correlation does not imply causation so just because it is a certain way does not imply something deliberately done by Apple. If it's too slow accessing the hard drive, it's because of the hard drive. Just let it go and enjoy the computer. 
Apple is purposely doing it due to compatibility issues with certain HD's would be my guess. Seagate 7200.4's in stock form at 3 Gbps have been known to beachball frequently when run at SATA 3 speeds. As the OP, I took the chance and throw in a 160gb G2 and so far it's been running great at SATA 3 speeds, whilst my 2009 MBP 15 could not properly run the exact same drive at SATA 3 speeds.
I have an SSD I put in the Opti-bay, which I boot from, and that shows 3 negotiated. But the Stock 7200rpm HDD which came with my MBP, which I use just for media (not for booting), shows 1.5 negotiated.
1.5 Gbps is 192 MBps. (capitalization matters; Gbps = gigabits per second, MBps = megabyte per second) This means that your hard disk would have to saturate that in order for this 3.0 v. 1.5 deal to make any sense as long as you're dealing with hard drives that have platters.
An SSD can easily saturate that; that's the only time it matters to have SATA 3.0.
My brand new i5 MBP has this same deal going for it; a 3.0 Gbps bus negotiating a 1.5 Gbps link with a stock Hitachi 320 GB hard drive. I won't complain since the drive can only hit 80 MBps, but if it could I'd look for ways to make the link go faster. It must not matter for some reason, and I can't imagine why.
An SSD can easily saturate that; that's the only time it matters to have SATA 3.0.
My brand new i5 MBP has this same deal going for it; a 3.0 Gbps bus negotiating a 1.5 Gbps link with a stock Hitachi 320 GB hard drive. I won't complain since the drive can only hit 80 MBps, but if it could I'd look for ways to make the link go faster. It must not matter for some reason, and I can't imagine why.
Some people seem to have missed the point, or not understood what has been rather plainly stated by several others.
The hard drive itself is only capable of the 1.5Gbps SATA standard. The chipset controlling the interface is capable of the 3Gbps SATA II standard.
Just like USB 2.0 devices do when plugged into a USB 1.1 port, the interface demotes the link speed to what the physical device supports. It's 'backwards compatible'.
Plug any 2.5" SATA II 3.0Gbps device into the ports in your laptop and you'll see the negotiated link speed change to 3.0Gbps.
It isn't a 'cap' put in place by Apple, but rather an industry standard which allows for backwards compatability with older drives.
SATA I devices are cheaper than SATA II, perhaps there's still a contract being fulfilled for HDD's? Most likely though is cost.