External HDD v slow r/w speeds

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markboynz

45 posts

Geek

#132352 18-Oct-2013 17:28

Hi everyone,

I'm having problems with an external HDD having very slow read/write speeds.

The HDD is a 3TB Seagate, purchased a few months ago. I don't believe it has always had this problem, but I can't be 100% sure.

I get very very slow transfer speeds on it, roughly 1MB/s average. I have a number of other external HDDs connected to this machine (5 total, I think), and testing software shows that I get between 12MB/s and 20MB/s on those. I have tried changing ports, but with the same issue.

Any thoughts of what I can do that is non-destructive? The HDD is 90% full, and at the transfer speeds I'm getting, getting the content off will be tricky, plus I'm not even convinced I have enough space to store it.

NB - the computer is an old custom build desktop, running XP. The ports are all USB2. I believe the HDD is USB3 - are there any known issues with external HDDs downgrading from 3 to 2?

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rhy7s

492 posts

Ultimate Geek

#917143 18-Oct-2013 17:40

Maybe double-check via a LiveCD e.g. http://www.majorgeeks.com/files/details/parted_magic.html (from there you'll also gain some other recovery options if the drive's going south).

timmmay

18496 posts

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#917155 18-Oct-2013 18:31

Back up the data immediately. Then format it and run a speed test.

markboynz

45 posts

Geek

#917159 18-Oct-2013 18:40

Backing it up may be difficult, because of the sheer size. I've just done a calculation, and I'm roughly 500GB short on space to back it up. Purchasing further storage is unfortunately out of the question.

Are there any further non-destructive options, before I have to choose 500GB of data to sacrifice?

kyhwana2

2537 posts

Uber Geek

#917177 18-Oct-2013 19:18

If it's that slow it could be because there's bad sectors and/or it's dying. If the stuff on it is important, I would back it up immediately!

rhy7s

492 posts

Ultimate Geek

#917178 18-Oct-2013 19:22

markboynz: Purchasing further storage is unfortunately out of the question

Probably best not to power it up then until you do have somewhere to dump it to with ddrescue.

andrewNZ

2487 posts

Uber Geek
Inactive user

#917180 18-Oct-2013 19:25

You don't know someone who you can borrow 500GB's off to make up for the shortfall?

Have you emptied all your recycle bins and cleared temp files? you might be closer than you think.

markboynz

45 posts

Geek

#917182 18-Oct-2013 19:30

Ok, so, the situation just got curiouser.

I finally got to actually be physically in front of the disks again.

Unplugged, plugged into laptop. Transfers at 60MB/s quite happily.

Swap the port with another drive that's working at 12MB/s.

Disks still transfer at the same speed, even with ports swapped.

I've run chkdsk, Seagate disk test, and a couple of others - no bad sectors or errors.

So, it appears that for some reason, there is a compatibility issue with that HDD and this particular computer. Could it be a driver issue? Is anyone aware of driver issues with USB3 drives on Windows XP (SP3, IIRC).

Device Manager sees it as a Seagate Expansion Desk USB Device, with a Microsoft driver dated 1/07/2001, revision 5.1.2535.0. In other words, as far as I can tell, the default USB Mass Storage driver. Should I be hunting around for something else?

timmmay

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#917183 18-Oct-2013 19:30

Is it data that can be compressed? Videos and music can't be, but documents, txt, etc, and some images (though not many) can.

You really need to consider your backup system. Right now you have a drive going bad and you can't back up your data. Perhaps it's time to delete non-essential data like rejected images, movies you can download again or get off a friend, etc, so your essential data is backed up.

markboynz

45 posts

Geek

#917185 18-Oct-2013 19:41

I currently have 12TB of data backed up, not compressable. Redundancy is just not financially viable at this point.

Anything that is catastrophic to lose is backed up redundantly, and for a 3rd time in the cloud. However, it would still be a massive PITA to have to recovered the rest of the data, hence my issue.

I appreciate that this is not an ideal backup situation, but unfortunately, it is what it is at the moment. I'm not overly concerned about the health of the drive, given the results achieved on a different machine, and repeated different testing showing the drive as healthy. What I am trying to work out is what is causing this specific slow transfer rate on this particular machine.

richms

25155 posts

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#917198 18-Oct-2013 20:20

Try a different power supply for the external drive. That was causing me massive loss in thruput on one of my machines, noisy cheap-as wall wart was messing with the USB communications.

Richard rich.ms

Inphinity

2701 posts

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#917201 18-Oct-2013 20:34

Is it a drive with an external power supply, or is it USB powered? I have seen some of the large-capacity USB3-powered drives that do not get enough power from older, not-quite-standards-meeting USB 1.1 or USB2 controllers. USB3 is designed to supply 900mA per port, USB2 and lower only 500 - while it's fine for nearly everything, it's borderline for some, and I've seen some older gear - especially laptops - not able to supply 500mA to any given port. So, if it's fubar on one PC, and not another, I'd say the USB ports on the fubar machine are struggling. It may be as simple as another USB device drawing too much current for the poor thing to manage. I just tested power draw on a 1.5TB USB drive I have here, and it's using 2.4W @ 5v under heavy load .. which is about 480mA, nearly the maximum for the USB2 standard.

Otherwise, it may well simply be a case of the troublesome PC not auto negotiating speed properly, the device going "Hey, can I go USB3?" and the PC going "Derp, whats that? Let's drop back to 1.1 just to be safe..." - USB1.1 has a throughput of only 12Mbps, which is just a touch over 1MB/sec in real-world copying.

richms

25155 posts

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#917206 18-Oct-2013 20:39

You can check for it being usb1.1 by setting the device manager to view devices by connection and seeing what USB controller the drive is showing as being connected to.

Richard rich.ms

markboynz

45 posts

Geek

#917246 18-Oct-2013 23:56

I've tried it on all three USB hubs in that computer, slow speeds on all of them. Just tried it on another desktop of similar age also running XP - transfer speeds are approx 40MB/s.

So, it would appear to be some specific issue with this drive and that PC. As best I can tell, the earlier commenter described it best - when it realises it can't handle USB3.0, it drops right to USB1.1 instead of USB2.0. Anyone have any suggestions of a way to force transfer rates?