The Seagate ST91000640SS is a 1TB 2.5-inch SAS hard disk drive designed for server use. With a rotation speed of 7200 RPM and a cache size of 64 MB, this drive offers fast read speeds of up to 136 MB/s. It features a hot swap design, making it easy to install and remove from the server. The silver-colored drive is part of the Constellation product line from Seagate, known for its reliability and performance in enterprise storage applications. Ideal for businesses requiring high-capacity storage solutions with SAS interface compatibility.