pmav

  ubuntu@c1-10-1-2-29:~$ dd if=/dev/zero of=test1 bs=1M count=512                                                               
  512+0 records in                                                                                                              
  512+0 records out                                                                                                             
  536870912 bytes (537 MB) copied, 5.43834 s, 98.7 MB/s

  ubuntu@c1-10-1-2-29:~$ dd if=test1 of=test2 bs=1M count=512                                                                   
  512+0 records in                                                                                                              
  512+0 records out                                                                                                             
  536870912 bytes (537 MB) copied, 5.869 s, 91.5 MB/s

  ubuntu@c1-10-1-2-29:~$ dd if=test2 of=/dev/null bs=1M count=512                                                               
  512+0 records in                                                                                                              
  512+0 records out                                                                                                             
  536870912 bytes (537 MB) copied, 0.60429 s, 888 MB/s