Compared with ordinary serial hard disks and SATA hard disks, what are the disadvantages of speed?

Serial hard drives and SATA hard drives are the same thing.

The serial port is faster than the parallel port.

ATA3 and SATA2 are a kind of transmission specification of the external interface of the hard disk, the theoretical speed of SATA2 data transfer is 300MB s, and the theoretical transfer speed of SATA3 has reached 600MB s, which is doubled; The speed here is only the speed of the external interface of the hard disk, but the overall performance is not like that, SATA2 or SATA3, they have to receive the data from inside the hard disk and then they can be handed over to the CPU for processing, subject to the traditional mechanical hard disk Winchester architecture, the current internal transmission speed of the mechanical hard disk has been bottlenecked, that is to say, from the external specification of SATA2, to the present internal transfer speed can basically be said to be stagnant, Therefore, this kind of hard disk (SATA3) is installed on the motherboard with the same SATA3 interface and the actual transfer speed of SATA2 is basically not much different, from many network tests, SATA3 with the corresponding motherboard after the speed wins, if it is not an evaluation, you can say that you basically can't feel any difference in actual use.

Serial port, parallel port,

Now it's generally serial! The parallel is old-fashioned! SATA1.

Serial port and parallel port are relative.

Hard disks that use SATA interface are also called serial port hard disks, whether they are SATA1, 2 or 3, they are universal, and the common 15+7 line is common.

As shown in the figure, the disk above is the serial port of SATA, as for the one that is 123 kinds, you can't see it just by looking at the appearance, and now the mainstream is SATA3, but it is common with the previous 1 and 2.

The following is the parallel port, that is, the IDE, which has long been eliminated.

The parallel port on the hard disk refers to the IDE interface The interface used for the old hard disk The speed is 100m per second, and the serial port generally refers to the SATA interface Now there are 3 generations of SATA (that is, SATA1, SATA2, SATA3) The speed is 150M, 300M, 600M, and the speed of the SATA depends on the speed of the computer SATA controller.

The serial port is described as a very wide lane; The parallel port has 8 lanes and can transmit 8 bits (one byte) of data at the same time. However, the parallel port is not fast, because the 8-bit channels interfere with each other, the transmission speed is limited, and when the transmission error, the 8-bit data must be retransmitted at the same time. The serial port will not interfere, and it is enough to resend one bit after the transmission error.

The biggest disadvantage of parallel is that 8bit needs to arrive at the same time, once it is inconsistent, it is required to re-transmit, the low frequency has no impact before, but once the frequency rises, it is difficult to do, and it needs a cache mechanism and a complete set of protocols to make up for it, and the cost is high, so it is simply serial high frequency to ensure bandwidth, not that it is not parallel but that the cost of high-speed parallel is high, and the real speed is parallel, but it is not necessary to use the desktop system.

Parallel port hard disk = IDE hard disk, currently eliminated, no new goods, mostly second-hand, repair, backlog of products, do not be fooled (civilian market).

Serial port hard disk = SATA hard disk, there are SATA1, SATA2, SATA3, three generations of products, basically universal, (most of the new disks are SATA3).

Serial port hard disks are --- faster than parallel port hard disks, which is determined by technology, but due to the different configurations of ordinary computers, it is not much faster (less than double).

!!Hard drive nominal speed ≠ actual speed!

In fact, the actual speed of serial port hard disk is about 100m (or less), and the parallel port hard disk is slower, which is about tens of m (or less).

Therefore: if the old computer does not have SATA port, you can buy a parallel port hard disk (second-hand) If the computer has SATA port, try to buy a new hard disk (safe).

Serial, of course. The parallel port is now in the stage of obsolescence, but the production has not been stopped. For now, the data stability of the parallel port is significantly stronger than that of the serial port.

If your computer is used to store data and work, it is recommended that you use the parallel port, which is suitable for young people to play large-scale online games. **Cheap. Running RPM is great for playing games.

It's actually quite simple to say.

In the early days, the frequency of all kinds of equipment on the machine was very low, and you know that the lower the frequency, the slower the speed! Just like the com port on the computer is also a serial port transmission method, it is very slow, and the fastest is only 512kbit

Equivalent to seconds. In this case, the invention of parallel port transmission technology, what does it mean, it can be imagined that many serial ports are used together, for example, there is only one pair of sending and receiving lines in the serial port line, and there are many pairs of parallel ports working at the same time, which is the meaning of parallel ports, so you can also see that the hard disk line of the parallel port is very wide, and there are many wires in it. But since there are many pairs of wire numbers sending and receiving at the same time, you can imagine wasting a lot of signals to control the connection and transmission.

With the development of computer technology, the current machine, the frequency is very high, but the frequency is high, the signal interference will occur, the higher the frequency, the signal between adjacent data lines is easy to affect each other, the probability of error is greatly increased, and the control of the signal is more and more difficult. So when the ATA specification reaches 133 (maybe higher, I don't know), there is no future, at least the fastest ATA hard drive on the market is also ATA133, most of which reach 100However, the serial data cable does not have this problem, because it only has one to send data, one to receive data, who affects whom, the control of data is of course relatively simple, basically as long as the frequency can be raised, the speed can be raised!

Therefore, it is logical for the serial port interface to replace the parallel port, although the serial port is still a little expensive, but it will be the world of serial port in the future!

I'm very simple and easy to understand.,It's tiring to type.,The landlord should add more points.。