firefox - What is the best file system and allocation size for a USB flash drive?

I'm considering using my 4 GB Kingston DataTraveler USB stick to store my Firefox and Thunderbird profiles for my laptop and desktop PCs.

I want to maximize performance when using Firefox. The question is: what is the best file system and allocation size for the fastest Firefox profile operation on a USB flash drive?

I'm using Windows 7 on both machines and I don't care about compatibility or the drive's lifetime. I just want to maximize performance. I could even use ext2 with the Ext2 IFS driver if that means it'll be faster.

I'm assuming (perhaps I'm wrong) that putting a Firefox profile on a USB stick would be a "lots of small files" usage. In that case, it seems that NTFS would perform best, but I'm not sure. Besides I found nothing regarding the best allocation size to use. Considering that the default allocation size is designed for hard drives (which have different characteristics), I'm assuming that the default allocation size is not the best.

Answer

As stated in the comments of the other answer suggesting using ATTO Disk Benchmark, I don't have a way to analyse the performance of ext2 (with ext2 IFS for Windows) on my USB drive.

So I gave it a try: I formatted using ext2, put my firefox profile on the flash drive, and then I did some surfing.

Surprisingly, ext2 behaves MUCH better than FAT32, NTFS or exFAT. Using one of these three filesystems I had constant freezing and unresponsiveness when using Firefox. Using ext2 there are still a few stutters but overall it is much more usable than the others. I have no idea why.

I'll mark this as accepted unless someone comes up with a better answer (other software to benchmark filesystem performance or an explanation as to why ext2 would be better).