USB 3.0 transfer rate decreasing after some time on Linux systems

On most contemporary Linux systems, support for USB 3.0 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. Here is how to do it.