Copying from one USB flash drive to another.

Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter

Peter Jason wrote:
Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter

USB flash drives have low seek time (1 millisecond).
There should not be quite as much variation, as you get
when transferring file-by-file using rotating hard drives.
Those have a significant seek time.

Flash drives slow down a bit, if block substitutions
are needed. (You've got some bad flash cells.)

Check the reviews for your two flash drives. See
if there is known variation in one or both of them.

*******

An SSD drive on the SATA bus, it has a seek time
of about 1/10th that of USB2. The reason for that,
is USB2 uses a polling method, and part of the time
is related to how the bus works. SATA is point-to-point and
not shared, so you're getting closer to the characteristics
of the flash chips themselves.

The lowest seek time, is for RAMDisks (a box holding a
bunch of memory DIMMs). Those can be connected to a
motherboard bus, and have latencies as low as 0.002 milliseconds.
Or about 500 times faster at it, than a USB2 flash drive seek.

Paul

Peter Jason wrote:
Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter


You might check to see if your antivirus program is checking the USB
drives. Mine has a tendency to automatically check any drive attached
to the system. Stopping the scanning makes such transfers much faster
for me.

"Peter Jason" wrote in message
...
Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter

One (but not all) of the USB sticks I've bought, had in the instructions
that it is beneficial to reformat the stick every once in a while.

Be sure to click "Restore device defaults" and uncheck the "Quick format"
box.

As I frequently transfer from a Win7 box to a XP one, I formatted the stick
on the XP box for the best compatibility - subsequently the 7 box was
telling me 11 hours to copy a few Gb to the stick, moving the copied so far
back and re-formatting as described above produced more acceptable results,
the transfer rate went from a couple of hundred kb/s to several Mb/s.

I've been told to expect cheaper USB sticks to be slower - the only cure for
that is a higher purchase price.

Ian Field wrote:


"Peter Jason" wrote in message
...
Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter

One (but not all) of the USB sticks I've bought, had in the instructions
that it is beneficial to reformat the stick every once in a while.

Be sure to click "Restore device defaults" and uncheck the "Quick
format" box.

As I frequently transfer from a Win7 box to a XP one, I formatted the
stick on the XP box for the best compatibility - subsequently the 7 box
was telling me 11 hours to copy a few Gb to the stick, moving the copied
so far back and re-formatting as described above produced more
acceptable results, the transfer rate went from a couple of hundred kb/s
to several Mb/s.

I've been told to expect cheaper USB sticks to be slower - the only cure
for that is a higher purchase price.

I found a pleasant exception to that, when the Best Buy sold
Lexar S73 32GB, for somewhere in the $20 range. For the same
price at another store, I got 1/4 the capacity and 1/8th the
speed. That was a sale price, perhaps back in January.
The regular price here, is a bit higher.

http://www.newegg.com/Product/Produc...tem=20-191-433

It's still competitive here. $25 at the moment.

http://www.bestbuy.ca/en-CA/product/...95a2932 den02

That last time I got something that good, was an OCZ Rally2.
And I think that one was more than $20 at the time.

I have no USB3 ports here, and on a USB2 port, the reads
on that thing are 35MB/sec (HDTune).

Paul

On Wed, 24 Apr 2013 18:29:10 +0100, "Ian Field"
wrote:



"Peter Jason" wrote in message
.. .
Win7 SP1

When so copying the transfer rate varies
constantly. The dialogue box gives a time of
copying from 1 to 6 hours. Is this because some
files are difficult to copy?
Peter

One (but not all) of the USB sticks I've bought, had in the instructions
that it is beneficial to reformat the stick every once in a while.

Be sure to click "Restore device defaults" and uncheck the "Quick format"
box.

I'll give this a try


As I frequently transfer from a Win7 box to a XP one, I formatted the stick
on the XP box for the best compatibility - subsequently the 7 box was
telling me 11 hours to copy a few Gb to the stick, moving the copied so far
back and re-formatting as described above produced more acceptable results,
the transfer rate went from a couple of hundred kb/s to several Mb/s.

I've been told to expect cheaper USB sticks to be slower - the only cure for
that is a higher purchase price.