USB Card Reader and SanDisk Firewire Card Reader - Mini Review

Yesterday I bought the SanDisk Extreme IV Compact flash card with the SanDisk firewire card reader for my Canon camera. Normally I use a no name USB card reader with USB 2.0 support to read the files from the compact flash to the hard disk. Today I made a comparison between the two readers and was astonished by the results. I measured "total bytes read" from the hard disk with the Management Console from WinXP.
Now the results:
USB card reader - Transcend 2GB compact flash 120x (picture below):

USB card reader - SanDisk 4GB Extreme IV (picture below):

Firewire card reader (SanDisk) - Transcend 2GB compact flash 120x (picture below):

Firewire card reader (SanDisk) - SanDisk 4GB Extreme IV (picture below):

Initially I couldn't see any difference between the Transcend card and the SanDisk card when I used the USB card reader. The difference between the two CF cards appears when I has used the fire wire card reader. It seems that a card reader can makes a difference. I have to note that there are definitely USB card reader, which can show the difference of this two CF cards.

Bibliography for further readings

[1]	Benz B., Erinnerungskarten, Die Technik der Flash-Speicherkarten, c't magazin für computer technik, Heise Zeitschriften Verlag GmbH & Co.KG, Hannover, 30. October 2006, p. 136-141
[2]	Feddern B., In die Karten geschaut, 164 Flash-Speicherkarten im Vergleich, c't magazin für computer technik, Heise Zeitschriften Verlag GmbH & Co.KG, Hannover, 30. October 2006, p. 142-153