ATA Hard Drive Vs. SATA

By Jason Artman

ATA and Serial ATA (SATA) are the two classifications of internal hard drives that can be purchased for your computer. Although SATA is a newer technology and capable of higher transfer rates, ATA hard drives are still produced because of the many computers that still use them. Understanding the differences between these drives can help you determine the best drive upgrade to fit your needs.


To identify whether your computer's current hard drive is an ATA or SATA model, examine it. The label will clearly specify which type it is. Additionally, examine the cables that are used to connect the drive. Every internal hard drive is connected to the computer using two cables; one for data, and one for power. If the data cable used by the drive is a wide, thin ribbon cable, it is an ATA drive. SATA cables are smaller--roughly 1/2 inch in width--and are generally red.


The primary benefit that the SATA interface has over ATA is speed. While ATA hard drives are limited to a maximum transfer rate of 133 megabytes per second (MB/sec), SATA hard drives have a transfer limit of 750 MB/sec. Bear in mind, however, that the speed of a hard drive is largely determined by the drive itself, not the interface. The fastest conventional hard drives in 2009 are only capable of a maximum transfer rate of about 142 MB/sec. Consider upgrading your computer to use conventional SATA drives only if you intend to use multiple hard drives in the same system. In a multiple-drive computer, the increased headroom of the SATA interface can truly be appreciated.


Following the introduction of SATA, you can expect to spend slightly more for an ATA drive; about $65 for a 500-gigabyte ATA drive compared to $50 for an SATA drive in 2009. This price difference will continue to widen as more ATA-based computers are replaced by newer ones using the SATA interface.

Using SATA Drives with an ATA Motherboard

Although SATA hard drives cannot be directly installed in a computer that can only handle ATA drives, you can use an SATA drive in your current computer by purchasing an SATA controller card. This is an expansion card that is installed into one of your computer's upgrade slots. With an SATA controller card, you can plug SATA hard drives into the controller card, rather than the computer's motherboard. This can allow you to upgrade the hard drive in your current computer while being sure that you will be able to continue using your new drive when you purchase a new computer. An entry-level SATA controller card can be purchased for less than $15.

New Computers

Although upgrading an existing computer for the sole purpose of being able to use SATA drives is questionable, there is no question that you should only purchase a new computer with SATA. The SATA drive interface is here to stay, and future high-capacity hard drives will only be available in the SATA form factor.