How long to backup 250GB using a USB2.0 Hard-Disk

Big.Wayne · 5 Oct 2006 at 20:43

Hi,

I just installed an external USB2.0 hard disk for a friend to backup his *My Documents* folder, he's got just shy of 250GB of personal data.

I'm using Norton Ghost 9.0 and set-it up to verify the backup after its finished, but it seems to take a *very* long time.

10 Hours & 42 Mins!!!!!!!!!!!!

As far as I can see the system is USB2.0 and is running WindowsXP SP2. I'm not sure how much of that time is the *verify* part (maybe that takes 5 hours?) but if anyone can quote me some transfer speeds that would be much appreciated, ta!

smids · 5 Oct 2006 at 21:39

USB2.0 will transfer at about 30Mb/s rather than the 48MB/s it is rated for. Factor in CPU usage for USB devices too.

Backing up - now was this a drive clone or a backup image? A backup image will often be processed and CRC checked etc. Acronic True Image created an image of about 40GB data in about 2 hrs (incl. verification) so it seems that your time is ok but only if it was performing a conversion. If not, and it was merely doing a drive to drive copy, then that is very slow.

2.5 hours is about 250GB data transferred @ 30MB/s.

As the image you posted suggests, this was an image which requires processing i.e. resizing and compiling into the image format. This is what took some time I assume.

Big.Wayne · 5 Oct 2006 at 21:46

Hi smids,

thanks for reply. Hmm I'm not sure what type of process it is doing but the resulting file has a .v2i extension.

I'm wondering if maybe it's working at USB1.0 speed?, it appears to be set-up fine in device manager, although it's a VIA KT400 chipset.

Also is there any difference between the cable used for USB1.0 and USB2.0? because I used an old cable that was laying around instead of the one included with the drive?

smids · 5 Oct 2006 at 21:53

I doubt it's working at 1.1 tbh. That chipset states it has 6 USB 2.0 ports. If the file created was a .v2i, this is a ghost image file and basically it all depends on the processor how fast it compresses the data. Think of it as RARing those files into an archive - that is essentially what happened to 250GB data - something I would expect to take that long, especially if verification was required after where it recalculates MD5 sums (or whatever check it uses, CRC most likely).

There are no differences in cable as far as I know - exactly like SATA1 and SATA-II - no difference.

Big.Wayne · 5 Oct 2006 at 22:09

smids said:
basically it all depends on the processor how fast it compresses the data

Hi again,

yes that would make more sense, it's an XP2400+ (T-Bred I think) so maybe its just taking its time.

Still I never did a 250Gb backup before, maybe thats 5 hours + another 5 hours (or so) to *verify* the backup. Not to much of a problem because it only does the one big *base* backup once a week and thats been set for sunday night so that its all done and ready to go for business start 9am monday.

thanks again!