[Francois_C]

So this was a lie when the Kobo was released and when they sold it to me.
I wonder how many weeks the Kobo would need to parse 30,000 x 1 MB e-books...
As I still use SDFormatter on Windows, which creates FAT32 partitions, do you mean that an ext2, 3 or 4 or reiserfs partition would be more reliable? This would not be totally surprising, as fat32 has lots of inconveniences. Well, I reboot on Linux and I format a clone of my current card. Let's try!

[Later] I did it. Formatting on Linux is like using a steam hammer to drive a nail. As gnome-format was not working, I used gparted which threatened me to erase terabytes of photos and data on other USB devices. I formatted in ext2, which seamed reasonably compatible, of course I had no access on a partition formatted as root at first (I like Linux, but all these boy-scouts games with passwords and prohibited zones, I hate that). At last I could write on my partition, copied the contents of my fat32 card on the new ext2 one, the files were properly parsed (some books appeared as new, because they had possibly been neglected on the fat32 card. But the card is not reachable from Windows even through the Kobo cord...

Conclusion: Kobo is not faster with an ext2-formatted card than a fat32 one, its system can recognize this file system, Kobo seems to use it as well as the fat32, maybe a little bit better, surely not slower.
But don't chose this method: you will not be able to write on your Kobo card on Windows, neither to use Kobo desktop nor Calibre on Windows. Calibre Linux probably works. I didn't try yet. But Fat32 is still the proper format...