Question Of The Week
PATA Vs SATA
What are the differences?
PATA and SATA are two types of Hard Disk Drives (HDD) being used at present, PATA being the older and SATA being the newer. Except in the way they connect to the PC, both are essentially the same.
PATA stands for Parallel ATA. SATA stands for Serial ATA. ATA stands for Advanced Technology Attachment which is a standard for interfaces (ports and cables) that allow you to connect storage devices to the motherboard of your PC. ATA is also known as IDE (Integrated Drive Electronics) which is simply a commercial name. Somehow it got stuck and is now being used interchangably with PATA.
1. Connection:
SATA interface is simpler and less fussy. SATA cables are long (upto 1 metre !!), thin, 7-pin cables. One end plugs into a port on the motherboard (labeled as Serial ATA Controller) and the other into a storage device like a Hard Drive or DVD Drive. The PATA cables, in comparison, look like a ribbon or belt, can connect two drives with one motherboard socket (labelled as IDE controller) and carry either 40 wires (older version) or 80 wires (newer version).
SATA cables are cheaper than PATA. With the SATA cables we can add or remove devices while the system is in operation (So-called Hot Swapping), but not with the PATA cables. The limited length of PATA cables (18 inches) prevent efficient routing and accessibility to component drives in the system. Moreover, their width prevent the system from cooling off by impeding air circulation inside.
2. Data Transfer Speed:
In SATA, data transfer occurs serially and is 1 bit at a time. In PATA, data transfer occurs in parallel and thus is a minimum of 16 bits at a time. But SATA is faster than PATA. How and why?
While first-generation SATA interfaces (known as SATA-1 Standard) had a data transfer rate of 150 MB/s (1.5 Gbit/s), even the latest models of PATA hard drives (ATA-7 Standard)could offer only a data transfer rate of 133 MB/second. It couldn't get better because as data transfer gets faster, synchronization of the data being transferred in parallel becomes a bigger problem. Although SATA-1 devices operated at best a little faster than PATA 133 devices, many people couldn't notice the difference.
Subsequently, second-generation SATA interfaces (SATA-2) with a 3 Gbit/s data transfer rate were developed, effectively doubling the maximum data throughput from 150 MB/s to 300 MB/s. Now SATA storage devices can transmit data to and from the rest of the computer over twice as fast as otherwise similar PATA devices. Wait... that is not all. SATA-3 standard with a 6 Gbit/s data transfer rate is on the way!!
3. Power Supply:
In PATA storage devices, there is a traditional 4-pin power supply called Molex which provides 5 Volts and 12 Volts. In SATA storage devices, there is a 15-pin power supply which gives a third voltage (3.3 V) in addition to the traditional 5 V and 12 V. This lower voltage allows faster signal ramping which is crucial for enhancing speed and reducing heat dissipation.
4. Jumper Settings:
One PATA cable supports two devices which must be set as master or slave with the jumpers provided. But if you are connecting only one device, usually there is no need for jumpers. Anyway, read the instructions (usually given on the label of the device itself) carefully.
One SATA cable connects only one device to the motherboard and is always the master. So SATA devices don't need jumpers generally. Yet they contain jumpers. Why? If you are connecting a SATA 2 device with 3 Gbit/s data transfer rate to your older motherboard which supports only 1.5 Gbit/s, you need to set the jumper on your SATA 2 device. Of course, it makes the use of SATA 2 standard meaningless!! But if your motherboard supports 3 Gbit/s, you can remove the jumpers provided with the SATA 2 device.
DVD drives are also now made available with SATA interfaces. Within a few years from now devices with PATA interfaces will become obsolete.