you're not going to believe this.

[Roland Smith]

On Tue, Jun 23, 2009 at 07:23:22PM +0200, Wojciech Puchar wrote:
> >> whatever.
> >
> > Not so. See http://en.wikipedia.org/wiki/Flash_file_system
> >
> > Most flash devices sold as harddisks have hardware that emulates a
> > traditional harddisk, representing it as a (P/S)ATA block device. Unless
> > you can bypass this, there is no need for a special filesystem.
> 
> yes this is exactly a problem. it emulates hard disk, which lowers 
> performance much. for example wear leveling and emulation small 
> blocks requires moving of data within flash, this lowers both performance 
> and lifetime.

Even a flash filesystem will have to do wear levelling. And you'll have
to gather writes to minimize the (slow) wiping of eraseblocks. In other
words, you'll be doing more or less the same that current hardware
does. But then in software, which is generally slower than dedicated
hardware.

The big difference is that it is much easier to tweak and change
algorithms when doing it in software.

Roland
-- 
R.F.Smith                                   http://www.xs4all.nl/~rsmith/
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