dd is obviously faster

# sysctl vm.drop_caches=3
vm.drop_caches = 3

# dd if=openSUSE_12.1_32_bit_live_CD_KDE.iso of=/dev/null bs=4M iflag=direct
165+1 records in
165+1 records out
694157312 bytes (694 MB) copied, 3.46756 s, 200 MB/s

# sysctl vm.drop_caches=3
vm.drop_caches = 3

# time cat openSUSE_12.1_32_bit_live_CD_KDE.iso > /dev/null

real    0m4.404s
user    0m0.020s
sys     0m0.988s