The full name of PATA is parallel ATA, which is the parallel ATA hard disk interface specification and the most common hard disk interface specification. The scale of PATA hard disk interface has a glorious history, from ATA33/66 to the highest ATA 100/ 133 and ATA 150 at present. The full name of SATA hard disk is Serial ATA, that is, serial ATA hard disk interface specification. At present, the general writing speed of PATA 100 hard disk is 65MB/s, while the writing speed of the first generation SATA hard disk is 150MB/s, the writing speed of the second generation SATA hard disk is as high as 300MB/s, and the third generation SATA hard disk has been upgraded to 600 MB/s, which is incomparable to PATA. The appearance of SATA hard disk interface specification will actually replace PATA, just as DDR replaces SDRAM.
How much faster can SATA be than PATA?
SATA appeared to replace PATA, so what are the main advantages of SATA compared with PATA? The first is speed, which is the most important thing. As mentioned above, the transmission speed of the second generation SATA is 300MB/s, and the transmission speed of the third generation SATA products is 600 MB/s. From the speed point of view, SATA has left PATA hard disk far behind. In addition, SATA is superior to PATA in transmission mode. SATA adopts single channel transmission, and PATA is multi-channel transmission. Some friends may literally think that PATA's multi-channel should be faster than SATA's single channel, but it is not. Let's look at the picture below.
Schematic diagram of standard ATA system connection setting
Schematic diagram of serial ATA system connection setting
As we can see from the above figure, because SATA's single data channel does not limit speed and frequency like PATA. The transmission speed of SATA transmission line is nearly 30 times faster than PATA. PATA must transmit 16 signals at a time on the data line. If the signal does not arrive in time or is delayed, it will produce wrong data. Therefore, it is necessary to reduce the speed of bit stream transmission to correct the error. SATA only transmits one bit of data at a time, and the bit stream transmission speed is much faster. It's like a dribbling game. Dribble one ball at a time is much easier than dribbling 16 balls at a time. Also, another improvement of SATA lies in its data connection, which is smaller in size, better in heat dissipation and quite convenient to connect with hard disk. Compared with PATA, SATA consumes less power, which is good news for notebooks. The unique CRC technology makes data transmission more secure.
When the frequency is low, the parallel port has great advantages, but when the frequency is high, the electrical performance of the parallel port is not as good as that of the serial port. When the frequency that the serial port can work normally is much higher than the frequency that the parallel port can bear, it will naturally surpass it. In addition, the current parallel memory architecture, especially the dual-channel (128BIT) motherboard, is difficult to manufacture and almost reaches the limit. Increasing the memory frequency will only put forward more stringent requirements for wiring. If it weren't for the reluctance of hardware manufacturers to take risks and completely change the production line, we should now use RAMBUS's XDR, which is high-performance and abnormal (compared with the bandwidth of dual-channel DDR 400 6.4 GB, it has 102GB, which can form 8 channels).
Secondly, from the point of view of data transmission, SATA has stronger anti-interference ability than PATA.
When parallel ATA transmits data, signals are prone to reflection and offset, and there is interference between signals.
SATA uses a method called differential signaling. For example, when the number 5 is transmitted to another device, it may encounter interference halfway, and 5 becomes 6; If we divide 5 into two lines, one is 8 and the other is 3, and let the difference between them represent 5, the middle will be disturbed and become 9 and 4 respectively, but the difference is still 5, so it has strong anti-interference ability. So the transmission rate can be high, so the broadband is enhanced.
In addition, SATA has a hot plug function that PATA can't match, which makes it more convenient to set up disk arrays. Because the data line of serial port only adopts four-pin structure, it is more convenient to install than parallel port, which is more conducive to reducing cables and heat dissipation in the chassis.
Second, the market price comparison
A good product must be linked to the market. The purpose of our new product is to remain invincible in the fierce competition forever. If a product technology is excellent, then if there is no market and it is not recognized by users, then no matter how high the technology is, it can only be overwhelmed by the market.
With the maturity of SATA technology and the continuous decline of price, the price of hard disk with SATA interface has entered the acceptable range of ordinary users. The hard disk price difference between SATA and PATA with mainstream capacity in the market is only about 50 yuan. Compared with the excessive price difference a year ago, SATA has really entered the users. Take Seagate Cool Fish hard disk as an example, it sells well in the market. The price of the traditional hard disk with 80GB PATA interface is 445 yuan, and the price of SATA hard disk is 495 yuan, which is just the price difference in 50 yuan. Faced with faster transmission speed and larger cache, I think most users should choose the latter.
Furthermore, as far as motherboards supporting SATA are concerned, the market is exquisite. Most motherboards already support SATA hard disks, and there is no need for third-party chips to support SATA. Even on the motherboard that focuses on the low-end market, we have seen the SATA interface. Because SATA interface has become the real mainstream in the market.
To sum up, SATA hard disk is superior to PATA in both performance and price. Faster transmission speed, larger cache and more stable performance have undoubtedly become the first choice for recently installed users. Of course, we can't ignore the existence of PATA hard disk. For ordinary users, if the money in hand is limited and the transmission speed of hard disk is not too high, then the cheaper price of ordinary PATA hard disk is more suitable for us to buy. In addition, PATA is also the best choice for old users to upgrade their hard disks. For hardware overclocking players, I think you should honestly choose PATA hardware, and the reason for this must be that all players and friends are bright in their hearts.
Finally, I would like to remind you that although SATA hard disk has hot plug function, ordinary users should forget this function, because this function can only be used under certain conditions, and the plugging and unplugging times of SATA data cable are very limited. Plug it in five times and replace it with a new data cable. In addition, compared with PATA hard disk, it is more troublesome to set the BIOS of the motherboard with SATA hard disk. You should be patient enough to make detailed settings. I won't talk about the specific setup process here. You can view the instructions of the motherboard according to different motherboards for detailed settings.