Comment 134 for bug 197762
Revision history for this message
| Neil Burlock (malone) wrote Re: file transfers on USB disk are very slow | #134 |
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0e1f616
(Get the code!)
No, it's not Ubuntu specific and Canonical didn't cause it.
Right now I'm copying between two SATA drives, connected to my PC via eSATA. So far a lousy 600MB has been copied and I'm already down to 5MB/s and falling.
Here is what I know about the problem:
It affects ALL hardware.
It affects ALL file copying connections to varying degrees: USB, network, SATA/eSATA.
In some instances, it also affects multitasking, all but locking the computer up despite little to no CPU use in System Monitor.
There are no error logs, messages or anything else that occur when the problem is happening.
In my experience, if you test for the problem and nothing seems to be wrong, then that's because you aren't copying enough data, you don't know how fast your hardware should be copying files, or you are lucky enough to only be subtly affected that time. Try copying more multi-gigabytes of data, several times and see if you can't get wildly different durations for the same data size. As I state above, all hardware I have tested is affected to varying degrees, some hardware shows minor performance degradation over time, some hardware is all but useless for file copying.
If you ask me, it's either the scheduler (GUI lockups with no CPU usage makes me think this) or whatever performs the actual file copy process. It's definitely not a USB problem because it affects network copying too.