windows 7 - How can I verify that my SSD is performing as it should?

I've got a brand new 256GB SSD (Crucial CT256M225) which should have stellar performance. However, on my (also brand new) Dell Studio 1557 with Windows 7 Professional 64 bit, it's only giving a performance index of 5.9. I realise the performance index should be taken with a bit of a pinch of salt, but I wonder whether something's wrong. Given this paragraph from this MSDN article on Windows 7, I'd expect to see a high 6.X or possible a 7.X figure:

In Windows 7, there are new random
read, random write and flush
assessments. Better SSDs can score
above 6.5 all the way to 7.9. To be
included in that range, an SSD has to
have outstanding random read rates and
be resilient to flush and random write
workloads.

In the Beta timeframe of Windows 7,
there was a capping of scores at 1.9,
2.9 or the like if a disk (SSD or HDD) didn’t perform adequately when
confronted with our random write and
flush assessments. Feedback on this
was pretty consistent, with most
feeling the level of capping to be
excessive. As a result, we now simply
restrict SSDs with performance issues
from joining the newly added 6.0+ and
7.0+ ranges. SSDs that are not solid performers across all assessments
effectively get scored in a manner
similar to what they would have been
in Windows Vista, gaining no Win7
boost for great random read
performance.

How can I diagnose any performance issues with either the disk or how Windows 7 is handling it?

Are there any particularly good tools you'd recommend?

One note of curiosity: I couldn't install the firmware update (to 1916) until I changed my BIOS handling of the drive to ATA mode; after installing the firmware I tried to boot the Windows installation DVD - but that only worked after turning it back to AHCI mode (which I've left it in).

Installing Windows 7 took longer than I expected - it sat at the "Windows is loading files" prompt for a very long time. Likewise it was on "Expanding files (0%)" for a long time. Since installation it's been fine though - but I don't know whether it's really providing quite as beefy performance as it should.

EDIT: My netbook with the 64GB equivalent drive has a performance index of 6.6...

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Update

Okay, so I've no idea what caused the change, but after trying loads of different things to work out what was wrong, I've rerun the WEI (about the 4th time in total) and the score has jumped to a far more respectable 7.3. I'm going to leave well alone now :)