[Nottingham] Writing into FLASH!

[Martin]

Martin wrote:
> OK, the optimisations quest continues, but it has also stirred a 
> question or two... ;-)
> 
> 
> For using flash devices (SSDs, memory sticks, USB keys or whatever name 
> you wish), one issue is their limited write cycles lifespan and the 
> killer of "write amplification".
> 
> A good brief explanation is on:
> 
> http://www.extremetech.com/article2/0,2845,2329594,00.asp

Also the write amplification makes writes very much slower...


I've just stumbled upon that with a certain memory stick. Using:

dd if=mandriva-linux-free-rc1-2010-x86_64.iso of=/dev/sdf

to write a 4GByte iso transferred at a mere 250kByte/s and took a few hours.

However, using:

time dd if=mandriva-linux-free-rc2-2010-x86_64.iso bs=1M | dd bs=1M | dd 
of=/dev/sdf bs=1M

took a mere few minutes!

7:38.31 elapsed 0% CPU

3998+0 records in
3998+0 records out
4192206848 bytes (4.2 GB) copied, 539.283 s, 7.8 MB/s


Anyone notice the difference?! :-)

Cheers,
Martin

-- 
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Martin Lomas
martin at ml1.co.uk
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