Serial advanced technology attachment (SATA) drives are a variety of hard drive common in modern computers. Older computers didn’t have SATA functionality and cannot use the drives. To work around this restriction, older computers may use an SATA card to allow it to plug in one or more SATA drives. A SATA card is a type of expansion card similar to a sound or video card. These cards offer access to large modern drives, but have a tendency to be buggy and difficult to configure.
A typical SATA card occupies a peripheral component interconnect (PCI) expansion slot. These slots are often used for installing additional network cards, port cards and sound cards. They are common on most standard personal computers. The only machines that don’t have expansion slots are extremely compact systems, like gaming computers or other portable desktop systems.
A SATA card allows users without SATA capacity to use SATA drives or users with an SATA system to use additional drives. These cards contain a controller, similar to the ones that come standard on a motherboard. This controller acts like an extension of the motherboard’s main systems, allowing the use of additional drives. A standard SATA card has room for one to four internal drives and zero to two external drives.
Depending on the age of the computer and the type of SATA card installed, a user will have different results. Some computers disable the installed drives on the computer in favor of the drives installed via the card. Other systems will have difficulty using internal and external SATA drives at the same time.
Most older motherboards used an parallel advanced technology attachment or integrated drive electronics (PATA and IDE) interface for their drives. These systems would commonly allow four drives to operate on a single computer. Some older systems have the four-drive limit hardwired into the system; in order to install new drives, older ports must be disabled.
Some SATA cards have a limit on the number of active ports at any given time. For instance, a card with two internal ports and one external port may be a ‘two-port’ card, even though it has room for three drives. When a drive is plugged into the external port, one of the internal ports won’t work. This is very common in older SATA cards and has become less common since.
While some SATA cards are simply drive expanders, some also contain a redundant array of independent disks (RAID) chip. This allows users to plug drives into the card and set up a RAID inside their computer. This raid is independent from the normal disk systems, making it well-suited for backups and long-term storage.