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Extremely low imaging transfer

fraudit
(@fraudit)
Member

Hello everybody,

I've just received a new blocker hardware - Wiebetech Ultradock v5 and started imaging at once.

However, I'm quite surprised with its imaging speed. I know it's not a drive-copier but… Here it is I connected an Intel SSD 160GB drive via SATA connection to the blocker and the blocker itself is connected to my laptop via eSATA. The resulting image (e01) is written directly on the laptop's HDD (Seagate Momentus 7200 rpm / SATAII).

The imaging speed is ca. 3.5-4.0 MB/s which seems for me unusually low. That means that imaging a 160GB drive will last ca. 11 hours! The only thing I can come up with is that the drive is fully encrypted - can it affect drive performance? Normal SATA drives I connected to compare had transfers around 92-96MB/s.

The software I use is FTK Imager 3.1 but the speed when using X-Ways was exactly the same.

I don't really think I could do anything wrong while connecting a pair of cables. 😉 Would you advise me what can be the bottleneck?

Many thanks in advance!

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Topic starter Posted : 21/08/2012 7:40 pm
athulin
(@athulin)
Community Legend

I don't really think I could do anything wrong while connecting a pair of cables.

(Have you looked at the system log or application log for errors or warnings? You don't have a failing RAM bank, for example? Would you discover one if you had?)

What equipment haven't you used in the same kind of set up before before? (Added that goes for software as well – you didn't upgrade some perfectly functioning device driver while you were at it?)

The write blocker, obviously. Does it get the necessary power? Have you read the manual thoroughly?

What about the cables? You did try alternate cables?

The source drive? You are giving it all the power it requires, too? Have you tried with another drive to see if it's the drive that's misbehaving?

(And just to cove all possibilities, the laptop is fully powered as well?)

On the off chance that you haven't done eSATA acquiry to internal drive before, try imaging to NUL That should remove the destination drive from the equation, and should be just as slow. If it isn't, I'd suspect that the laptop SATA controller(s) may not be up to the job you're giving it. In that case, using an external eSATA card might help. But laptops are rarely data transfer speed monsters …

If it is as slow, the only remaining component seems to be the write blocker. Time to call Wiebetech support …

You should find the expected performance off the product specification sheet of the SSD hard drive, as well as that of the write blocker.

ReplyQuote
Posted : 21/08/2012 10:46 pm
mscotgrove
(@mscotgrove)
Senior Member

Try reading another drive with the existing cables etc.

Are you compressing the E01 image. An encrypted drive will not compress so will be very slow trying, and save no space on the outp[ut device.

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Posted : 21/08/2012 10:47 pm
fraudit
(@fraudit)
Member

@athulin - Thanks for the tips! There were no changes in my laptop configuration. I believe I've checked all (or saying safer - most of) possibilities related to malfunction. I tried also different cables and ports, even connected via USB3 with no speed change. There is enough power as the laptop is set on high performance plan and the blocker is powered separately. The laptop itself is rather a strong one - i7@2.0GHz and 16GB RAM.

@mscotgrove - Well, I did use compression, though it was set at 3 level. However, it's not the case I'm afraid as the speed isn't higher with no compression.

Some additional information - the drive is encrypted with WinMagic SecureDoc.

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Topic starter Posted : 21/08/2012 11:29 pm
marcyu
(@marcyu)
Active Member

Try the imaging the drive in dd raw format. If it doesn't reach at least the same speeds as your previous write blocker, get an RMA number and return the unit.

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Posted : 22/08/2012 1:58 am
fraudit
(@fraudit)
Member

Thanks marcyu - I've imaged the whole drive yet it took ca. 11 hours. Well, happens….

But as I said before - connecting other non-encrypted drive gives me a full imaging speed. So my concern is whether there is something with the blocker that it cannot handle encrypted HDDs or it is just a unique situation and every encrypted disk will take a long time to duplicate. Can anyone answer that for me?

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Topic starter Posted : 22/08/2012 5:04 pm
joachimm
(@joachimm)
Active Member

Some additional information - the drive is encrypted with WinMagic SecureDoc.

FYI when the drive is encrypted using compression is a waste of time. Encrypted data should be highly random, and not worth while to compress, otherwise the encryption algorithm would not be secure.

Write blockers cannot often deal with drive-level (ATA) encrypted drives, SecureDoc seems to be a software solution so that should not be an issue. Since it's a normal drive containing encrypted data.

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Posted : 22/08/2012 6:32 pm
mscotgrove
(@mscotgrove)
Senior Member

The next test should be to crate a disk with the encrypted data on. Then try and image that drive. It will show if it is a data problem, or physical drive problem.

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Posted : 22/08/2012 8:10 pm
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