On 08/04/13 20:32, mick wrote:
Hi all
Does anyone have any experience of using USB 2.0 to ethernet adaptors? Ignoring the apparently magical ability to get more than 280 Mbits/s of adaptors advertised as "USB 2.0 to gigabit ethernet", what is the realistic maximum throughput anyone has experienced with such devices, and on what architectures?
I am considering options for building a very small, low powered in-line F/W and some of the devices I am looking at only have one ethernet port (but often two or more USB ports).
I'm not sure about the potential bandwidth you'll likely achieve but what I will say is that USB interfaces and devices are CPU bound..so CPU usage will grow with network traffic faster than it would if you had a "real" NIC.
On a modern PC it isn't so much that you'd notice...on a small embedded system such as you may be using for this project it will become a factor, particularly if more than one interface is in use.
Also watch out because some (and one very popular *cough*) low power embedded systems already have their internal NIC hanging off a USB interface...the bandwidth isn't per port it's per controller bus, of which anything small and low power is only likely to have one.