Parallel ATA (EIDE and IDE) standard cables are for internal computer storage devices. For many years ATA provided the most common and the least expensive interface for hooking up drives. By the beginning of 2007 (EIDE and IDE) are largely been replaced by Serial ATA (SATA) in new systems.
First-generation SATA interfaces, also known as SATA/150 or unofficially as SATA 1, communicate at a rate of 1.5 gigabits per second (Gbit/s). First-generation SATA devices operated at best a little faster than parallel ATA/133 ide devices.
Given the importance of backward compatibility between SATA 1.5 Gbit/s controllers and SATA 3.0 Gbit/s devices, SATA/300's autonegotiation sequence is designed to fall back to SATA/150 speed (1.5 Gbit/s rate) when in communication with such devices.
|SATA 1.5Gb/s||SATA and eSATA 3Gb/s|
|Frequency||1500 MHz||3000 MHz|
|Real speed||150 MB/s||300 MB/s|
Maximum cable length for eSATA is 2 meters. SATA offers advantages over the older parallel ATA interface: primarily faster data transfer, the ability to remove or add devices while operating (hot swapping) (only when the operating system supports it), and thinner cables that let air-cooling work more efficiently.