What is the difference between USB3.0 and 2.0 Nowadays USB 3.0 data interface is becoming more and more popular. Newly launched notebooks will basic
What is the difference between USB3.0 and 2.0
Nowadays USB 3.0 data interface is becoming more and more popular. Newly launched notebooks will basically have multiple USB3.0 ports. Even the B75, Z77, and other new motherboards that are compatible with the new generation of IVY processors are compared with SNB platform motherboards. The big difference is that motherboards such as B75 and Z77 have added USB3.0 high-speed interfaces.
With the continuous popularization of USB flash drives, the era of high-speed USB3.0 has also arrived. For the new USB flash drives, how to distinguish whether it supports USB3.0 high-speed transmission? What is the difference between USB3.0 and 2.0? Let’s discuss it together. Let's look at the difference between USB3.0 and 2.0 and how to distinguish it.
From the appearance of USB, USB2.0 is usually white or black, while USB3.0 is changed to a "tall" blue interface.
From the perspective of the USB socket pins, USB2.0 uses a 4-pin design, while USB3.0 uses a 9-pin design, which is more powerful than USB3.0.
From the appearance of the USB male port, see what is the difference between USB3.0 and 2.0. The USB3.0 interface part is marked with "SS" style, while USB2.0 is only marked with the ordinary USB general logo.
At present, some notebook computer USB interfaces have provided support for both USB2.0 and USB3.0, so what is the difference between USB3.0 and 2.0? It can be distinguished by the color of the interface.
From the point of view of the transfer rate, the theoretical value: the transfer speed of USB 3.0 is 4.8Gbps, which is 10 times that of USB 2.0. That is, 4.8Gbps=600MB/S.
What is the difference between USB3.0 and 2.0? The question of whether the USB flash drive supports USB3.0 can be distinguished by the appearance of the usual USB flash drive. Under normal circumstances, the USB3.0 USB flash drive will be recognized.
Let's talk about USB3.0 together
1) USB 3.0, what a popular word! The USB 3.0 interface standard was only announced in November 2008. It has been less than 3 years since there have been a large number of USB 3.0 products on the market: USB 3.0 motherboards, USB 3.0 mobile hard drives, USB 3.0 USB flash drive, USB 3.0 card reader, USB 3.0, the following introduces the knowledge of USB3.0 interface, I hope it will be helpful to novice friends.
2) According to the media, the transmission speed of USB 3.0 is 4.8Gbps, ten times that of USB 2.0. Yes, it is G-level, but this is a bit, not a byte. Just like you pull a 4Mbps network cable, the actual download speed can only reach 512KB/S. Because 8 bits = 1 byte, that is, 4.8Gbps=600MB/S, this is still a theoretical value.
3) 600MB/S, really fast. But to achieve this speed, these two bottlenecks must be broken: motherboard interface and storage medium. You rushed to the Computer City, bought a USB 3.0 mobile hard drive and tried it back, and found that the speed is still USB 2.0. This bottleneck is probably due to the motherboard interface. USB 3.0 motherboards, although various manufacturers have launched them because Intel does not currently integrate a USB 3.0 host controller in its chipset, USB 3.0 motherboards are not yet popular and relatively expensive. The so-called USB 3.0 motherboards you see now are all transitional products. Most of them use a third-party USB 3.0 master chip to bridge two blue USB 3.0 ports. PS: If your desktop motherboard does not have a USB 3.0 interface, but there is still a free PCI-E slot, you only need to buy a PCI-E to USB 3.0 adapter card; for notebooks, buy a PCMCIA to USB A 3.0 expansion card (USB 3.0 ExpressCard) will do. This card sells for about 70 yuan, and the D720200F1 is still used.
4) Even if there is a USB 3.0 interface from the motherboard, the mobile hard disk used is also a USB 3.0, can the actual transmission speed reach 600MB/S? According to Steak (www.ZhaoNiuPai.com), I can tell you with certainty: no show at the moment! Limited by the mechanical structure of the hard disk, the internal transmission speed of the mainstream 3.5-inch 7200 rpm 500G hard disk will not exceed 150MB/S, and the internal transmission speed of the 2.5-inch 5400 rpm 500G mobile hard disk is lower. I used to test with a 120G mobile hard drive equipped with USB 3.0 interface on a host equipped with a Gigabyte G41 motherboard, Pentium E5800 CPU, DDR 3 1333 2G memory, and USB 3.0 Express Card. ATTO showed that the read and write speeds were only up to 45MB/S and 47MB/S (the bottleneck has appeared in the hard disk, which is the transmission speed of the hard disk). Of course, some people can buy an SSD solid-state drive to try, the speed will be much faster (the new SSD, its read and write speed has reached 500MB/S).
5) USB 3.0 interface, for some devices, is just a gimmick for merchants. For example, USB 3.0 keyboard and mouse, compared with USB 2.0, is there any difference between USB3.0 and 2.0? Yes, but it doesn't make sense, because the amount of data that the keyboard and mouse need to transmit is very small, and USB 2.0 is more than enough.
6) USB 3.0 flash drives, the speed bottleneck lies in the main control and FLASH chips used. Some time ago, I took a steak to Huaqiangbei and saw the best U disk with a write speed of 96MB/S and a read speed of 110MB/S. The silver-can master is used, and the FLASH seems to be Samsung or Micron SLC (life and speed are both large Higher than ordinary MLC ). At that time, I was thinking, if the laptop uses SSD, will the actual transmission speed of this U be faster?
7) USB 3.0 card reader, similar to the main control + FLASH of the USB flash drive, but this FLASH exists in the form of "plug-in". The actual transfer speed depends more on the memory card itself. Different memory cards have very different speeds. The common ones on the market are cards with a write speed of only a few MB to a dozen MB.
8) Regardless of the bottleneck problem, the transfer rate of the USB 3.0 interface depends on the size and quantity of the transferred files, which is the same as USB 2.0. For the same 100M data, the transmission of a single file is much faster than hundreds of fragmented files. In any case, USB 3.0 is a trend, it provides the possibility for faster file transfer, although there are various speed bottlenecks.
Update on May 17, 2012: The theoretical interface rate of USB 3.0 is 5Gbps, but it uses an 8/10b encoding method to encode 8-bit data into 10 bits for transmission. Therefore, the theoretical data transfer rate of USB 3.0 is 5Gbps/10=500MB/s.
USB 2.0 does not use the 8/10b encoding method. Therefore, the theoretical interface rate of 480Mbps can be used to transmit data. That is, the theoretical data transmission rate of USB 2.0 is 480Mbps/8=60MB/s.
The transfer rate of USB 3.0 is 500/60=8.3 times higher than that of USB 2.0, instead of 10 times.
USB 3.0 enhanced power supply cannot fail to mention. The same is 2.5 inches, and the same is the 5V power supply voltage, but the mobile hard disk has high and low current requirements. The maximum current supply capacity of the USB 2.0 port is only 500mA. When there is no external power supply, people often encounter situations where some mobile hard disks with higher power consumption cannot work. Even if they can barely work, it is not uncommon to damage the hard disk. Sometimes it can be used when the mobile hard disk is connected to the USB 2.0 port on the back panel, but it may not work when it is connected to the front USB 2.0 port (because of the large voltage drop due to poor wires). USB 3.0 has improved the power output capability, each port has a maximum of 900mA, and the combined output power is 4.5W, which has been able to meet the needs of most mobile hard drives.
In any case, the data transmission speed of usb3.0 has indeed been greatly improved compared to usb2.0 . With the gradual popularity of USB3.0, USB3.0 will gradually replace the current USB2.0 in the future. Those who are interested in Friends may wish to learn more about the difference between USB3.0 and 2.0.
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