USB2 to USB2 Xfr speed?

  • Thread starter Thread starter Homer
  • Start date Start date
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Homer

Does anyone know about how long it should take to transfer 50 GB of data
from one USB2 external drive to a 2nd USB2 drive? I am trying to do this
but it is taking over 24 hours and that seems to be way too long.

Thanks..
JohnS
 
Previously Homer said:
Does anyone know about how long it should take to transfer 50 GB of data
from one USB2 external drive to a 2nd USB2 drive? I am trying to do this
but it is taking over 24 hours and that seems to be way too long.
Click to expand...

I usually see ~15MB/s. With a transfer to the same USB controller,
this scould be aggregated BW. Ad some switcover time and call it 10MB/s.
This gives 5000s to read and 5000s to write, a bit less than 3 h.

At USB 1 speeds it would be around 30h.

Hmm. Seems whatever you do to copy (if both drives run as USB 2.0)
is very slow. Losts of small files? Buffering turned off (if it is
Windows)? That could do it.

Arno
 
Homer said:
Does anyone know about how long it should take to transfer 50 GB of
data from one USB2 external drive to a 2nd USB2 drive? I am trying to
do this but it is taking over 24 hours and that seems to be way too long.
Click to expand...

Yeah, something's ****ed.
 
Yeah, something's ****ed.
Click to expand...
Yea, ****ed is right. I think though that it is most likely just the
fact that it is tons of small files in multiple folders and sub folders.
Actually, I should have said that what I am doing is backing up from one
drive to another using Windows XP's built in backup program. That alone
may be one of the issues. Anywaze, thanks for the info.
 
Yea, ****ed is right. I think though that it is most likely just the
fact that it is tons of small files in multiple folders and sub folders.
Click to expand...

Its more likely the problem is that its running at USB1 speed instead.

Easy to test the two possibilitys.
Actually, I should have said that what I am doing is backing up from
one drive to another using Windows XP's built in backup program.
That alone may be one of the issues.
Click to expand...

Yeah, its better to use something decent like True Image instead
for other reason as well. Leaves the standard NTBackup for dead.
Anywaze, thanks for the info.
Click to expand...

No problem, thats what these technical groups are for.
 
Homer said:
Does anyone know about how long it should take to transfer 50 GB of data
from one USB2 external drive to a 2nd USB2 drive? I am trying to do this
but it is taking over 24 hours and that seems to be way too long.

Thanks..
JohnS
Click to expand...

If you're using a Mac or linux, you should be seeing in excess of 40MB+
per second.

Windows? Lucky to get 15MB / sec....


Odie
 
If you're using a Mac or linux, you should be seeing in excess of 40MB+
per second.
Click to expand...

Unfortunately not. I see 25MB/s with Linux (Agrosy enclosures, nForce4
chipset and both drives, kernel 2.16.7.7).

When I copy from disk to disk, I see 12.5MB/s transfer rate, i.e.
25MB/s real bus rate. Without the hub this stays unchanged, so it
seems to be a chipset or driver limitation.

Arno
 
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