Speed Of USB 1.1/2.0

[Admin]

1.1 = 12Mbps = 1.5MBps
2.0 = 480Mbps = 60MBps

Traditionally, USB mice and keyboards only need 1.5Mbps to function; exceptions are gaming input devices that require 12Mbps, and they include the Logitech G5, G7, G15 and Razer Copperhead. These higher-end gaming products send way more location feeds thru USB; hence, more bandwidth is required. Generally, the performance levels (1.5Mbps & 12Mbps) are grouped under 'Original USB' by the USB Promoter Group.

Additional notes from Alex Esquenet - our engineer friend based in Belgium: "A fast usb host can achieve 40 MBytes/sec. The theorical 60 MB/sec cannot be achieved, because of the margin taken between the sof's (125 us), so if a packet cannot take place before the sof, the packet will be rescheduled after the next sof. On top of that, all the USB transactions are handled by software on the PC. For instance, a USB host on a PCI bus will send or receive the data via the PCI bus; the stack will prepare the next data in memory and receive interrupt from the host."