Continuous write, 100 mb:
Image stored on a filesystem: 26.964s
100x CF Card: 36.572s
USB Stick: 1m28.938s
Disk Partition: 2.599s

Random write (write 1mb, skip 2mb, loop)
Image: 21.111s
CF: 49.917s
USB: 1m29.354s
Partition: 2.832s