Comment 201 for bug 131094

Thanks for these detailed informations. So you suggest that the IO scheduler is not giving enough priority to tasks other than the file copy; that's an interesting way of finding the cause of the problem, indeed! I suggest you try the new kernel, and if it's not fixed, go to the upstream report and explain them your case. You can find many different scripts to test the system's responsiveness there, and you'll notice that's really tricky (long thread...).

Now, another test would be interesting: copy the same file from the SATA disk to itself, and see if there's any difference with what you've already done (in terms of responsiveness, not speed, because it will be different, obviously).