Is there a way to find the data speed used by existing usb 2.0 controller. I had attached a usb pcie card at my system and the specification of shows, that it will be around more than 12mbps of transfer speed. But when I had attached my network drive on that the data is very slow. I had a intranet website that lags when anyone start working on data processing. I had updated the drivers and also ensure that there is not other app using the nas storage. Can anyone provide some kind of device which can help me to calculate what is the data transfer speed of a port.