SATA I SATA II SATA III Difference

Difference between SATA I, SATA II and SATA III and the benefit for an SSD

Serial ATA (SATA, abbreviated from Serial AT Attachment is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives and optical drives.

close-up_of_data_and_power_connectors sata_drive

What is the difference between SATA I, SATA II and SATA III?
SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s, is the first generation SATA interface running at 1.5 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 150MB/s.

SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 300MB/s.

SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. The bandwidth throughput, which is supported by the interface, is up to 600MB/s. This interface is backwards compatible with SATA 3 Gb/s interface.

SATA II specifications provide backward compatibility to function on SATA I ports. SATA III specifications provide backward compatibility to function on SATA I and SATA II ports. However, the maximum speed of the drive will be slower due to the lower speed limitations of the port.

Example: A SanDisk Extreme SSD, which supports SATA 6Gb/s interface and when connected to SATA 6Gb/s port, can reach up to 550/520MB/s sequential read and sequential write speed rates respectively. However, when the drive is connected to SATA 3 Gb/s port, it can only reach up to 285/275MB/s sequential read and sequential write speed rates respectively.

bobthehelper hd-x-ssd

Standard hard drives cannot reach these speeds. Only SSD’s can take advantage of the speed available with SATA II and SATA III connections inside your computer. That is why it’s a good idea to upgrade your computer or laptop to an Solid State Drive (SSD). Plus the fact there are no moving parts and they create less heat is better for your system.

A typical 1 TB HDD can deliver around 100 to 115 MB/s in my experience on a SATA III connection, while some SSD’s can deliver up to 550 MB/s (that’s mega bytes per sec, not bits) read speeds.

If you’re interested in upgrading your computer/laptop phone me on 0418 530 133 or email me at robert@bobthehelper.com.au

For more information on what an SSD is etc have a look at this link.