Odd USB transfer issue

[mikeymikec]

I'm seeing this happen more often with my computer, with various USB storage devices (all external hard disks, one via an enclosure, and the other two are external hard disks by Seagate/WD with USB interfaces), and it's worrying me.

For example, just now I wanted to transfer a large file from my computer to a USB hard disk connected to an enclosure. Windows (7 64-bit SP1) reckoned that the transfer was going at 100MB/sec (bear in mind, USB 2.0), and now it has been sitting there for about two minutes stuck on 80% remaining.

On this occasion there are a heck of a lot of disk errors in the event log (pointing at the external disk), so either the external disk has stopped responding completely or 'other', but on other occasions there aren't any disk errors, and yet a large file seems to get transferred in bursts - transfer for a few seconds at "100MB/sec", then stop for about 10 seconds, then do another burst. Normally I would expect it to max out the USB 2.0 bandwidth and go fairly consistent at that pace (assuming that neither source or destination are getting low on space or are heavily fragmented).

My PC spec:

http://www.mikeymike.org.uk/mikes/mypc.txt

I probably will upgrade my chipset drivers. I don't have any other issues with my system, nor does the event log show anything particularly worrying otherwise.

- edit - I've just reconnected the drive that threw a load of errors, and I'm getting the bizarre transfer behaviour again, though it let me transfer a file to the disk this time. I'm transferring another load to it now, and for a while it was spiking at crazy speeds (460MB/sec, 100MB/sec, etc) then idling for ages, but then it reverted to normal, constant transfer speeds, then went crazy again.

The USB-connected disk I'm transferring to is an old one, a noisy Seagate 400GB, so there's simply no question as to whether it is doing something at a given time or not because the 'click' sound it has given when accessing data has been so obvious since the day I bought it brand-new. I think I'll run a full disk check on it at a convenient time (thanks to MS's belief that Win7's chkdsk consuming all available RAM and slowing the system down is desirable/expected behaviour).

I wonder if this might be an oddity to do with Microsoft Security Essentials in the way that it scans large files. I'm using Process Explorer to monitor disk I/O. I haven't been using it that long, so it may have something to do with it. I just used WinDiff to compare the file I just transferred to make sure the destination and source files are identical, and they are, however it took about two seconds to compare a several-hundred meg file.

 

[icanhascpu2]

Well, first off USB 2.0 doesn't operate anything close to 100MBs let alone 460. So those readings are either wrong, or youre on USB 3.

What is the CPU doing while this is happening? This is usually the signs of a dieing drive, Id back up everything I could overnight using better software than just a windows file copy. Also check the SMART status of the drives.

 

[mikeymikec]

The CPU is idle. Of course USB2 doesn't operate at those speeds ~25MB/sec and a few megs more if you're lucky. I don't have any USB 3.0 capable devices (though the board is, those ports aren't in use).

I don't think a drive is dying except maybe the 400GB one which showed a load of disk errors, but I have this problem with two other disks via USB (the Seagate and WD external disks), and if the internal disk was dying, I doubt it would show solely through SATA <-> USB transfers.

I might try removing MSE and see whether the behaviour differs.

 

[Cerb]

I'm seeing this happen more often with my computer, with various USB storage devices (all external hard disks, one via an enclosure, and the other two are external hard disks by Seagate/WD with USB interfaces), and it's worrying me.

For example, just now I wanted to transfer a large file from my computer to a USB hard disk connected to an enclosure. Windows (7 64-bit SP1) reckoned that the transfer was going at 100MB/sec (bear in mind, USB 2.0), and now it has been sitting there for about two minutes stuck on 80% remaining.

That's regressive Windows behavior. You really can't get more than about 35MB/s from USB2, and the more small files, the worse it will be. Windows is not telling you how much it has written to the drive, nor what speed it i actually writing to it at. If it can do it faster in memory, you get that mostly that speed being displayed, which is bogus. I love getting 200MB/s on my thumb drive (it's actually 2-3MB/s).

Drive errors, OTOH, should be checked out. Use vendor diag tools for Windows to check it out. If they are clean, and you have no remapped sectors, then run a chkdsk (properties->tools->error-checking) on each. If it is a FS issue, not physical HDD issue, quit removing them w/o ejecting first .

If all that doesn't help, or diags come back clean but you are getting actual disk errors (as opposed to filesystem errors), consider buying a good USB cable. Many included ones are bottom of the barrel quality, even from storage vendors who shouldn't be doing that crap. Verifying that it is the cable of course requires compatible cables that you can swap between devices.

 

[mikeymikec]

Two different cables in use - I've got a two-into-one USB cable which one of my external disks requires and I use it for the second, then the old 400GB drive is connected via an enclosure and a USB printer cable.

I wouldn't mind if it was just the Windows copy progress UI which was giving out weird figures, but it'll show crazy figures, then get to 80-99%, stop for ages, then finish. On Process Explorer today, after upgrading the chipset drivers, it allegedly bursted at about 100MB/sec, then calmed down to a more realistic 25-30MB/sec rate for quite a while, then the copy progress UI sat at 99% for about 15 seconds before completing.

The only other USB device connected and 'live' at the time is my Logitech wireless mouse.

Removing MSE didn't help.

 

[mikeymikec]

I just tried running robocopy to copy a folder structure with only large files in, and it managed to do 26MB/sec average despite the spiking.

I guess everything is ok except the 400GB disk (probably).

I'm running WinDiff to compare the folder structure I just copied (not to the 400GB disk), looks ok so far.

 

[Cerb]

I wouldn't mind if it was just the Windows copy progress UI which was giving out weird figures, but it'll show crazy figures, then get to 80-99%, stop for ages, then finish. On Process Explorer today, after upgrading the chipset drivers, it allegedly bursted at about 100MB/sec, then calmed down to a more realistic 25-30MB/sec rate for quite a while, then the copy progress UI sat at 99% for about 15 seconds before completing.

I'd like it to not do that, too. For devices 'optimized for quick removal', IMO it aught to only show info based on data committed to the device. Cache-based is fine for permanent storage, where only a total power failure would make it it false.