Why does the USB 3.0 transfer rate decreases after some time on Linux systems?
On most contemporary Linux systems, support for USB3 functionality has moved from separate kernel modules to the kernel itself. On such systems, the kernel memory which is allocated for use with USB 3.0 is predefined and set to a relatively small value (e.g. 16 MB on a typical 32-bit Ubuntu 12.04 System). This value is usually enough for reading from an external HDD or similar applications, but in the case of machine vision applications it is way too low.
For this reason you have to increase allocated memory to at least 256 MB. In the manual of the USB 3.0 industrial camera mvBlueFOX3 you will find a description how to do this.