- USB 2.0 is forward and backward compatible. This means that USB 2.0 products are able to work in PCs with USB 1.1 or 2.0 interface. As such these products can be operated in 3 different specifications.
- USB 2.0 Low Speed - USB operation at 1.5Mb/s (same as USB 1.1 normal transmission speed)
- USB 2.0 Full Speed - USB operation at 12Mb/s (same as USB 1.1 maximum transmission speed)
- USB 2.0 High Speed - USB operation at 480Mb/s in PCs with USB 2.0. Its maximum speed is only 480Mb/s, which is 40x faster than USB 1.1. And the normal transmission speed is 60Mb/s, which is 5x faster than USB 1.1.
Due to the above information, there are vendors who have changed their upcoming USB 1.1 products to USB 2.0 full speed instead. In fact, these products are actually operating at the speed of USB 1.1 and not the actual speed of USB 2.0. Therefore, you may wish to double check if the product you're buying is certified as USB 2.0 high speed.