For now, now using USB 3.0 USB 3.1 interface of USB is not a few, even high-end U disk even broke the 300 MB/S read and write speed, U disk can have such result looks good, but compared to the SSD still has some gap (older don't compare the SSD). So why is it that the gap between the usb flash drive and the SSD is so big?
There are differences in master control
U disk is not only a master and master are divided into two categories, the first: is the ordinary USB master, direct flash particles, via USB main control chip control, the U disk performance is usually not more than 100 MB/s read and write speed, master like this type of USB stick bits wide in 8-16 bit, performance is couldn't get on.
The other is to use SSD control, which is often found in high-end USB drives, and SATA's interfaces are routed through USB. Many SSD master chips are actually 32bit compact instruction set processor architecture, which can be seen on many mobile devices.
Speaking of which, we understand the difference between the price and the speed of the high-end and ordinary usb drives. Since high-end usb drives are also using SSDS, why doesn't the access speed compare with solid-state drives?
Than SSD mainly has two points in it, as the high-end USB transfer through SATA interface USB when this loss to part of the read/write performance to some extent, from USB 3.0 upgrade to USB 3.1 interface and can save a little performance.
Compression and non-compression algorithms
There are two compression and non - compression algorithms of U disk main control algorithm. Master compression algorithm for data, which can identify the processor for "compressed data" to a certain proportion of compressed, then the compressed good data written into the flash memory, is helpful to reduce the amount of data written to the flash memory; Instead of the main control of the compression algorithm, the data type is not distinguishable, and the flash memory is directly written to the data, which speeds up the life of flash memory.
Most high performance usb drives will not be lower than 64GB-1TB capacity, and the large capacity supports the non-compressibility algorithm's main control, thus achieving good performance under the non-compression algorithm.
The two barriers, the conversion and master control, obviously make it impractical to chase the USB USB flash drive with the speed of the SSD, but all belong to the same memory, and the speed with SSD storage is also ok.