Copying from one USB flash drive to another.

P

Peter Jason

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
 
P

Paul

Peter said:
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
 
K

Ken

Peter said:
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.
 
I

Ian Field

Peter Jason said:
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.
 
P

Paul

Ian said:
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/Product.aspx?Item=20-191-433

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

http://www.bestbuy.ca/en-CA/product...spx?path=c43b222a23d1954895f38bbb95a2932den02

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
 
P

Peter Jason

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
 
J

Joel

Peter Jason said:
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

I think it depends on the SPEED of the flash drives and USB. And I don't
think you need to care what the box may say but whatever *real* TIME is.

IOW, the computer may estimate the *current* SPEED and and the speed may
vary depending on the performance of your computer. IOW, it can be
transfering at 100MB/s at one time and 1MB/s at other time.

And if the system lockup then it will be FOREVER no mater what the box may
say.

Example if the speed is USB1 then it's slower than USB2 and slower than
USB3, and sometime I notice the USB2 device runs faster on USB3 port
 
J

Joel

Ian Field said:
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 don't see how the price will effect the speed, unless you compare the
lower price because of the lower speed.

IOW, if the exact same USB device cells at Best Buy for $100 and Wal-Mart
for $10, then they both should have the exact performance (beside
Anti-Wal-Mart feeling)
 
J

Joel

Ian Field said:
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.

Also, many years ago when memory card was very new I paid *hundreds* of
dollars for 16MB (Mega *not* Giga). And it was slow like dog then
 

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