If the files you are fuzzing are small, then you could just create a couple of gigs of tmpfs ramdisk with something like "mount -t tmpfs -o size=2G none /mnt/so

If the files you are fuzzing are small, then you could just create a couple of gigs of tmpfs ramdisk with something like "mount -t tmpfs -o size=2G none /mnt/somewhere" and put your fuzz directory on there. Then the impressive number of writes are all to memory, which should pose no problem.