Western Digital has acquired solid-state drive maker SiliconSystems. The $65 million transaction is already complete, and SiliconSystems has become WD's Solid-State Storage business unit. The purchase will provide the current market leader in 2.5-inch drives with a way into the growing SSD market. Based in Aliso Viejo, Calif., SiliconSystems was established in 2002, and makes SSD products for communications, industrial, embedded systems, medical, military, and aerospace applications. SiliconSystems' product lineup includes SSDs with a variety of interfaces, including SATA, EIDE, PC Card, USB, and CF, in 2.5-inch, 1.8-inch, and CF.