The answer to this question is application specific and is very dependent on the external master's capabilities.
In theory, the host can transfer data at a rate of 53 MBytes/sec. On a system using a PCI card to provide the USB 2.0 interface, the maximum bulk transfer rate is typically 20 Mbytes/sec. For more information on this subject please see the Cypress Application Note, "Measuring Delivered USB 2.0 Bandwidth with an EZ-USB FX2 Development Board." You can download this application note using this link http://www.cypress.com/?rID=12933.