I gave it a go to check it out. Mind you I have two 520's in R0 but I am pretty sure that my speed is not slow...
Large 11GB file
Network-->520 = ~30-36 MB/second (Network is active and speeds fluctuated)
520<-->520(same drive) = 150-250 MB/second Averaged about 150 MB/sec
Small files (2000 files from SYSTEM32)
520<-->520 = 150 MB/sec
