Ian,

> Because JFFS compresses data and YAFFS does not, this also has to
> be factored into any figures. How does the test data compress
> etc., who much real flash i/o is (was) performed?

Of course JFFS2 compression was turned off.

> The fact that your numbers show that Yaffs is faster in the
> nandsim test, indicates to me that the underlying performance of
> the real NAND device and hook-up is a large factor in any
> measured performance.  nandsim really doesn't simulate NAND.

Well, first, nandsim does simulate NAND :)
Then, I'm totally aware that this is not a comprehensive comparison.
Still I think that we can make some conclusions based on the results,
and the conclusions are that yaffs2 is slower than expected on write
operations for 2k page flashes and slower on mount than expected on
512b flashes, and that's something we'd better profile.

Best regards,
   Vitaly