Slow internet speed? Mouse card? There is interference with USB 3.0!

Many things are now moving towards wireless development, such as WiFi, wireless keyboard and mouse and so on. But what the friends may not know is that the computer's USB 3.0 and 2.4GHz wireless devices are interfering!

This matter has existed for a long time. Intel announced the specific situation after the emergence of the USB 3.0 specification, but it is not paying attention to it in daily use. In the past two days, the editor inserted a USB 3.0 mobile hard drive into a computer with wireless WiFi+2.4G wireless mouse+Bluetooth (also 2.4G) keyboard. Oh my God, it’s almost crashing, and the hard drive's read and write speed has dropped drastically. The mouse freeze is extremely serious, the keyboard hitting feedback is delayed, and even the network speed is stuck.

Suddenly the editor thought of this-when USB3.0 is in use, the 2.4G frequency band adds about 20dB of noise, which is enough to interfere with the normal use of wireless devices (2.4G), including the devices mentioned by the editor. In principle, the spread spectrum processing of USB3.0 causes its spectrum to cover from 0Hz to 5GHz, but after Intel measurement (a main member of the USB 3.0 specification), the interference power decreases with frequency, about -60dBm in the 2.4G band , The 5G frequency band is only -90dBm, and almost all of our commonly used wireless devices are used in the 2.4G frequency band, interference is inevitable.

To solve this problem, we can start from several aspects. The first is to add shielding to the interface of the USB 3.0 device. If the shielding measures are appropriate, the frequency band interference problem can be effectively reduced. The method is also very simple: tin foil can be done (many food packaging is), and tin foil is included in the interface. For example, a mobile hard disk is fine. If you don't have it, you can also put it in an iron box.

If you find it too ugly, there is also a way to buy an extension cable to keep the USB 3.0 interface away from various receivers (mouse, keyboard), but this method is useless for the built-in Bluetooth.

Another point is that WiFi uses 5G frequency bands instead of 2.4G frequency bands as much as possible. This is also a commonplace problem. After switching to 5G, the interference problem will be solved a lot.

This interference problem seems to be caused by the USB 3.0 design specification, but it is not. Many devices have almost zero shielding measures in order to reduce the price. This will happen. For example, the mobile hard disk box in the hands of the editor, although it is not a copycat, Because the price is too cheap (over 20 yuan), the shielding design is hardly done, and interference is inevitable.