I haven\'t bothered publishing my accumulated benchmarks of various cheap flash media (SD cards, CF cards, USB sticks), but since you asked, I might just put something up. Note, however, that the random-write IOPS performance typically varies between 3 (yes, I\'m serious - three) and about 20 for SD cards (SanDisk and Lexar seem to fare reasonably well, and Kingston aren\'t too bad). Some CF cards fare better (e.g. Pretec SLC ones are extremely good and comparable to the performance of a proper SSD, but they are also nearly double the price per GB of a good SATA SSD). USB sticks with a Kinsgon controller are quite good, typically between 100 and 200 random-write IOPS.
Random-read IOPS are generally quite good, typically in the 500-1500 IOPS range (depending on the card), so this isn\'t a problem. It is the random-write IOPS that tend to kill the performance.
With practically every cheap flash device I have seen, the write performance tops out at using 64KB blocks, which usually indicates this is the erase block size. As for tuning, I usually use the following.
mkfs.ext4 -b 4096 -E stripe-width=16 -O ^has_journal
Deadline I/O scheduler also helps a bit because it allows reads to overtake writes.
Or you could just get a USB->SATA adapter and plug a proper SSD into it and be done with it once and for all...