It uses the same pins and the same protocol as internal SATA, thus eSATA drives offers the same high speed data transfer rate. However, eSATA can support the cable length of two meters compared to the one meter supported by SATA.
It is worth mentioning that unlike USB and Firewire interfaces, eSATA does not have to translate data between the interface and the computer, this enhances data transfer speed, also you do not need additional chip. Since eSATA offers such fast transfer rates, it has been a popular external hard drive interface used by video editors, audio producers, and other media professionals.