Hard Drives: ATA versus SATA
The performance of computer systems has been steadily increasing as faster processors, memory, and video cards are continuously being developed. The one key component that is often neglected when looking at improving the performance of a computer system is the hard drive. Hard drive manufacturers have been constantly evolving the basic hard drive used in modern computer systems for the last 25 years, and the last few years have seen some exciting developments from faster spindle speeds, larger caches, better reliability, and increased data transmission speeds.
The drive type used most in consumer grade computers is the hearty ATA type drive (commonly called an IDE drive). The ATA standard dates back to 1986 and is based on a 16-bit parallel interface has undergone many evolutions since its introduction to increase the speed and size of the drives that it can support. The latest standard is ATA-7 (first introduced in 2001 by the T13 Technical Committee (the group responsible for the ATA standard)) which supports data transfer rates up to 133MB/sec. This is expected to be the last update for the parallel ATA standard.
As long ago as 2000 it was seen that the parallel ATA standard was maxing out its limitations as to what it could handle. With data rates hitting the 133MB/sec mark on a parallel cable, you are inviting all sorts of problems because of signal timing, EMI (electromagnetic interference) and other data integrity issues; thus industry leaders got together and came up with a new standard known as Serial ATA (SATA). SATA has only been around a few years, but is destined to become “the standard” due to several benefits to be addressed in this Tech Tip.
The two technologies that we will be looking at are:
ATA (Advanced Technology Attachment) – a 16-bit parallel interface used for controlling computer drives. Introduced in 1986, it has undergone many evolutions in the last 18+ years, with the latest version being called ATA-7. Wherever an item is referred to as being an ATA device, it is commonly a Parallel ATA device. ATA devices are also commonly called IDE, EIDE, Ultra-ATA, Ultra-DMA, ATAPI, PATA, etc. (each of these acronyms actually do refer to very specific items, but are commonly interchanged)
SATA (Serial Advanced Technology Attachment) – a 1-bit serial evolution of the Parallel ATA physical storage interface.