What is the difference in an original SATA and a SATA 2 drive? is a SATA 2 backwards compatible?
Cheers

SATA II is the natural evolution of SATA. When a SATA II Hard Disk Drive is attached to a SATA II controller, additional features are enabled:

• 300 MB/s interface - double the old 150 MB/s interface. In reality, the platter speed limits performance to around 80 MB/s.
• Hot plugging - add and remove non-system disks on the fly
• Native Command Queuing (NCQ) - also supported in some SATA configurations, NCQ is usually standard in SATA II

The SATA II controller must support all of the above features, but the Hard Disk Drives do not. This is why SATA II is often called SATA 300, to emphasise the performance of 300 MB/s interface supporting Hard Disk Drives.

SATA and SATA II are protocol and mechanically compatible. Motherboards that do not expressly support SATA II can use SATA II Hard Disk Drives, while Motherboards with SATA II controllers can use SATA Hard Disk Drives.