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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 which supports data transfer rates up to 133MB/second. According to different articles I’ve found, this standard is supposed to be the last update for this aging technology.
In 2000 it was realized that parallel ATA was reaching the limit of it’s data transfer capability. 133MB/second is the limit of the technology due to data loss and electromagnetic interference. This prompted the invention of the Serial ATA interface (SATA). SATA is a fairly recent standard and has only been around for a few years. Because SATA can support data transfers at about 150MB/second. Future versions of SATA (like SATA 2) will support data transfer of up to a projected 600 MB/second.
One benefit of SATA for system builders is the fact that the cables which connect the drive are so much smaller than the regular tick grey ribbons which connect IDE drives. The reduced size of the wires allow for better airflow which is becoming increasingly important as processors get faster and as systems support more RAM. All that speed and memory can make a lot of heat as you are well aware. Anything that helps keep your PC running cool is a good development.
Another noticeable change is the different power connector. Even though some drives still offer the 5v 4 pin power connector, most SATA drives come with a 15pin 250mV power connector. This reduces the load on the computer’s power supply which will also help decrease in-case temperatures.
One final benefit of the SATA interface is the ability to hot swap drives. Hot swap means that you can pull your drive from your machine and replace it with a different disk without restarting your computer. This will be especially helpful for people who are not familiar with configuring a RAID array for backups.
In conclusion, I’m excited for the advance in technology that SATA has brought to the world. It’s been almost 20 years since IDE was introduced and it's about time the technology was updated.
BTW, great writeup, should help out a lot of people wondering about PATA/SATA.
SATA's definitely the way to go tho :)
Chip-
The SATA interface uses LVDS (low-voltage differential signaling) which is where the 250 millivolt figure comes in. However, the SATA power connector includes 3.3V, 5.0V, and 12 Volt power supply connections. As such, the voltages used don't directly affect case temperature; It is the product of voltage applied multiplied by current through the load (power) which affects case temperature. The gain here is that voltage regulators are no longer needed to reduce the 5 Volt supply voltage to 3.3 Volts to operate the logic in the drive. (Typical inexpensive series regulators generally accomplish such a voltage reduction by generating heat with the extra energy, so we get rid of those by directly supplying a 3.3 Volt rail.)
Jim
