Edit:
Ooops, sorry, I just noticed that I posted in the wrong board ... it should have gone to "Linux - General"




Hi,

I recently copied about 2 Terabytes from one USB 3 harddisk to another. During this, the system was kind of stuttering, although the CPU load was minimal.
The most eye-catching effect was the mouse and keyboard responsiveness. Yes, my mouse and keyboard are USB devices, but connected to USB 2 ports, so it's even a different controller:
The USB 2 ports are on the southbridge, while the USB 3 ports are on a separate chip.

But input devices are not the only thing that's not correctly responding (although most things I do on the computer are depending on input). I tested watching a video from the internal harddisk. It was palying good most of the time, but every few minutes, it stopped for a split second and then continued. Copying it to /tmp did not make a difference (/tmp is a tmpfs, meaning it's a ramdisk).

Is this a hardware or software problem ?

Mainboard: ASUS Sabertooth 990FX (with ASMedia USB 3 chip)
CPU: AMD Phenom II 1045T

I'm asking because copying took a few hours. And I think I will need to do such a copy procedure regularly in future.

How is the USB 3 chip connected to the system?

Normally these chips are capable to use DMA.

It looks like it's connected via PCI. At least, lspci shows the controller. Unfortunately, I don't have more info.

What distribution are you using?

I ask because it is known that on systems using cgroup control over the GUI will cause this problem. It happens due to memory utilization by the copy (which can be quite large) will cause extra user swapping within the cgroup that is doing the copy.

For a test, switch to a console terminal and do the copy as a different user/root.

You can switch back to the GUI while the copy is going and find out if the problem still exists...