[ale] Microcenter Free USB sticks

[David Tomaschik]

On Mon, Feb 21, 2011 at 2:24 PM, Ron Frazier
<atllinuxenthinfo at c3energy.com> wrote:
> This inspired me to do a bit of spur of the moment testing. I have a PNY
> Attache 4GB memory stick, which is supposed to be pretty good. I think
> it said high speed on the package, but don't remember for sure. I did
> some testing writing 5 Ubuntu ISO's to the memory stick and reading from
> the stick.
>
> For Linux, I just dragged files in the file manager.
>
> Linux - copy TO stick FROM internal HDD - 9.6 MBps
> Linux - copy FROM stick TO internal HDD - 18.3 MBps

Not surprising.  Flash media typically has better read than write performance.

>
> For comparison.
>
> Linux - copy FROM internal sata 5400 RPM HDD TO same HDD different
> folder - ext4 -> ext4 - 29.4 MBps (It seems to me this should be much
> faster.)
> Linux - copy FROM internal sata 5400 RPM HDD TO same HDD different
> folder - ext4 -> NTFS - 12.1 MBps (I found this interesting.)

Also not surprising.  The NTFS support is most likely the ntfs-3g
driver, which is implemented in userspace, and is probably sub-optimal
due to reverse engineering of the NTFS.

> I think about 30 MBps is as fast as I ever get on USB, even to / from a HDD.
>
> Now, here's how Windows did. I used the Teracopy application to copy.
>
> Windows - copy TO stick FROM internal HDD - 10 MBps (Slightly faster
> than Linux.)
> Windows - copy FROM stick TO internal HDD - 15 MBps (Slightly slower
> than Linux.)
>
> For comparison.
>
> Windows - copy FROM internal sata 5400 RPM HDD TO same HDD different
> folder - NTFS -> NTFS - 18 - 23 MBps (Slightly slower than Linux ext4 ->
> ext4.)
>
> Here's another interesting point. One other time, on another computer, I
> did some testing from ONE internal SATA 7200 RPM drive to ANOTHER
> internal identical drive on a different sata port.
>
> Linux ~ 30 MBps
> Windows ~ 60 MBps

This surprises me somewhat, but I suspect filesystems play a big role in this.

> Windows was twice as fast. Something other than the interface is slowing
> Linux down. However, I was thinking I should be over 200 MBps on both,
> considering the 3 Gbps interfaces. Also, none of these experiments even
> make the CPU breathe hard.

The speed of the interface far exceeds the speed of reading from
spinning platters, especially if seeking is involved.  (This is why
fragmentation is terrible.)  According to Seagate, the internal
transfer rate of SATA drives is about 1/3 of the interface speed.  So
a purely-linear read task should yield about 100 MBps.  Of course, it
takes LARGE files to make read/write tests useful unless you purposely
disable various caching mechanisms.  (And then you still have to deal
with filesystem overhead.)

> Sincerely,
>
> Ron
>


-- 
David Tomaschik, RHCE, LPIC-1
System Administrator/Open Source Advocate
OpenPGP: 0x5DEA789B
http://systemoverlord.com
david at systemoverlord.com