Hard drives are available with a number of different interfaces, though the most common currently available are Ultra-ATA and SATA. Ultra-ATA is the older of the two technologies, and can support transfer speeds of up to 133MB/s. Serial ATA is still relatively new, and can support transfer speeds of 150MB/s and above. There are additional interfaces available, such as SCSI (Small Computer System Interface), though these are more specialised and generally found in servers rather than home PC�s.

The ATA specification has gone through a number of changes during the past twelve years since its introduction, including a significant boost in transfer rates. Drives using the Ultra-ATA interface are easily recognisable by their use of ribbon cables to transfer data. The Ultra-ATA interface is also used on the vast majority of optical drives, so it will be a considerable time before the newer SATA technology is fully adopted.

SATA drives use a much thinner cable to transfer data, which is one of their advantages over the older Ultra-ATA counterparts. They are also capable of higher transfer rates, with standard SATA capable of moving 150MB/s and the faster versions now capable of shifting 300MB/s. SATA also uses a dedicated channel for each drive, meaning that drives get full use of the available bandwidth. This is another significant advantage over Ultra-ATA drives, where bandwidth may be shared between two drives on the same channel.

Currently, there is little difference in price between SATA and Ultra-ATA drives, so which you should go for will depend on your current set up. Older machines will still use the Ultra-ATA interface, whilst many newer machines may support the newer SATA interface. If possible, go for the SATA option as you will benefit from better performance and less cable clutter.

There are also a variety of SCSI drives available, and although these are more commonly found in servers, they are not entirely unheard of in the home environment, particularly on older machines. The largest drives currently being produced are only available in Ultra and Serial ATA format, though some of the highest performance drives are still SCSI drives. The other advantage of SCSI drives are that up to 15 devices can be used on a single channel, which can be advantageous should you require a vast array of storage. However, SCSI drives are significantly more expensive than their ATA counterparts hence its limited popularity.

There are many more technical differences between the technologies outlined above, though it is important not to get wrapped up in these too much. The bottom line for most users is performance, reliability and price, and for the vast majority, the best balance is struck by SATA based drives. The incompatibility with older machines may limit upgrade options for some, but the majority of mid-range systems sold now include native SATA support.

Hard drives are available with a number of different interfaces, though the most common currently available are Ultra-ATA and SATA. Ultra-ATA is the older of the two technologies, and can support transfer speeds of up to 133MB/s. Serial ATA is still relatively new, and can support transfer speeds of 150MB/s and above. There are additional interfaces available, such as SCSI (Small Computer System Interface), though these are more specialised and generally found in servers rather than home PC�s.

The ATA specification has gone through a number of changes during the past twelve years since its introduction, including a significant boost in transfer rates. Drives using the Ultra-ATA interface are easily recognisable by their use of ribbon cables to transfer data. The Ultra-ATA interface is also used on the vast majority of optical drives, so it will be a considerable time before the newer SATA technology is fully adopted.

SATA drives use a much thinner cable to transfer data, which is one of their advantages over the older Ultra-ATA counterparts. They are also capable of higher transfer rates, with standard SATA capable of moving 150MB/s and the faster versions now capable of shifting 300MB/s. SATA also uses a dedicated channel for each drive, meaning that drives get full use of the available bandwidth. This is another significant advantage over Ultra-ATA drives, where bandwidth may be shared between two drives on the same channel.

Currently, there is little difference in price between SATA and Ultra-ATA drives, so which you should go for will depend on your current set up. Older machines will still use the Ultra-ATA interface, whilst many newer machines may support the newer SATA interface. If possible, go for the SATA option as you will benefit from better performance and less cable clutter.

There are also a variety of SCSI drives available, and although these are more commonly found in servers, they are not entirely unheard of in the home environment, particularly on older machines. The largest drives currently being produced are only available in Ultra and Serial ATA format, though some of the highest performance drives are still SCSI drives. The other advantage of SCSI drives are that up to 15 devices can be used on a single channel, which can be advantageous should you require a vast array of storage. However, SCSI drives are significantly more expensive than their ATA counterparts hence its limited popularity.

There are many more technical differences between the technologies outlined above, though it is important not to get wrapped up in these too much. The bottom line for most users is performance, reliability and price, and for the vast majority, the best balance is struck by SATA based drives. The incompatibility with older machines may limit upgrade options for some, but the majority of mid-range systems sold now include native SATA support.