Why is my SATA controller capping the link speed? This is what it says in my System Profiler under the Serial-ATA page:
Vendor: NVidia
Product: MCP79 AHCI
Link Speed: 3 Gigabit
Negotiated Link Speed: 1.5 Gigabit
Description: AHCI Version 1.20 Supported
The link speed is as expected (3 Gigabit), but I don't see why it is negotiated into a 1.5 Gigabit link speed.
The drives attached to the SATA interface are a Hitachi 320GB 5400rpm
hard disk drive and a MATSHITADVD-R UJ-868
superdrive.
I have a MacBook Pro 5,3 with Snow Leopard 10.6.8. My question is why the negotiated link speed is lower than the actual link speed.