Get a FREE fully-working copy of Steganos Security Suite 7 (worth £49.99) when you sign up to the Practical PC Newsletter. What is SATA?
Confused by SATA and PATA? Not sure what hard drive to buy?
SATA or Serial ATA is the replacement for the older Parallel ATA or PATA standard for hard drives and related devices such as DVD burners and tape streamers. Whereas the older standard was typically used over a wide ribbon cable that was often difficult to neatly run around the inside of a PC, SATA used a far thinner cable and new connector making it much easier to work with. SATA also brings a new standard for power connections although the first generation of SATA hard drives often used the same 4 pin Molex connector as has been used in PCs for years. Modern PSUs and drives now tend to use the proper power connectors though which like the data cables are more compact. Be aware though that the proper SATA power cables can be fragile and ensure they are inserted and pulled out straight, any sideways movement can damage the connector's shell - indeed this aspect of SATA has been fairly widely criticised.
Benefits
Apart from thinner cabling and its associated advantages such as improved airflow for a cooler running PC (hopefully!) and general tidyness, SATA also allows for faster transfer speeds although as with power cables, the first generation of drives worked at much the same speed as their older PATA counterparts. This is now starting to change though.
Other features that SATA brings as standard is hot swapping (the ability to remove and change a drive whilst the PC is running) and improved reliability due to uprated data checking. Finally, suitably equipped drives and motherboards support NCQ or Native Command Queing which allows for multiple data requests to be handled more efficiently by allowing the drive to choose the order in which requests are serviced allowing it to minimise read-head movement and thus improve access and speed of retrieval across the requests. In reality, this has little impact outside of server environments though. SATA also allows for slightly longer cables - 1 metre as opposed to 0.46 metres for the older PATA cables.
Installation is also simpler - the old PATA requirements of a master and slave drive set by jumpers has gone - with one drive per cable, you no longer need to worry about getting the right jumper settings.
Variations and Speeds
There are currently four SATA variants. The first generation supported speeds of up to 1.5Gbit/s or 150 megabytes per second once the overheads are taken in to account. SATA 300 doubles this and longer term, this doubles again with a 6.0 Gbit/s standard that is not yet used to any great extent beyond specialised systems. Finally, External SATA or eSATA allows for a connection method to external devices at speeds of up to 2400 Mbit/s such as hard drives or DVD burners that are more commonly connected by the rather slower USB2 (480 Mbit/s) or FireWire (393 or 786 Mbit/s) standards. eSATA allows for a maximum cable length of 2m which is less than both USB and Firewire so the choice as to which method you use is down to specific situations rather than a blanket recommendation one way or another.
Upgrading
If your existing motherboard only has PATA connectors, you can buy PCI based adaptors that let you add SATA drives but be aware that performance won't be what it could be compared to a native solution. A far better option is to upgrade your motherboard to one that has SATA and ideally PATA too so you can still access your old drives if needed. It is also worth choosing a motherboard that also supports RAID and/or NCQ if that is important to you. The motherboard shown here sports six SATA sockets - four standard orange ones along the bottom and two on the left hand side which support RAID and NCQ via a seperate chipset.
SATA or PATA
This is really a non question now. Any new purchase really should be SATA unless there is a good reason otherwise. If your motherboard is PATA and you have no free PCI slots for an adaptor card then PATA is the only choice, you'll probably also want PATA for DVD burners and the like as SATA ones are still thin on the ground. For everything else, if your motherboard supports it, the speed, better cabling and features such as hot swapping make it the best choice for adding hard drives.
