The combined SATA speeds on 2010 MacBooks are limited to about 330 mbps. Merely 30 megabytes over a single SATA connection.
UNLESS (wait for it) you have a firewire connection active. Then both SATA connections work at full speed, no problems.
I hooked up dual 64gb Samsung 830's running in raid in my 2010 2.8ghz i7. Which are interesting because the max write is low at 160 mb/s since its a small drive.
I easily max out write speeds in RAID at 318 mb/s, but in write i hit the 330 mb/s limit and can't get higher. It's not until the Firewire port is active that the SATA 2 ports start to work normally.
It's been documented for a couple years now. I'm really surprised i don't see much of anything more about it.
This sucks.
http://macperformanceguide.com/Reviews-MacBookProCore_i7-SATA-Bizarre.html
http://macs.about.com/b/2010/05/17/macbook-pro-sata-firewire-issue.htm
UNLESS (wait for it) you have a firewire connection active. Then both SATA connections work at full speed, no problems.
I hooked up dual 64gb Samsung 830's running in raid in my 2010 2.8ghz i7. Which are interesting because the max write is low at 160 mb/s since its a small drive.
I easily max out write speeds in RAID at 318 mb/s, but in write i hit the 330 mb/s limit and can't get higher. It's not until the Firewire port is active that the SATA 2 ports start to work normally.
It's been documented for a couple years now. I'm really surprised i don't see much of anything more about it.
This sucks.
http://macperformanceguide.com/Reviews-MacBookProCore_i7-SATA-Bizarre.html
http://macs.about.com/b/2010/05/17/macbook-pro-sata-firewire-issue.htm