dd bs comparison

$ time dd if=/dev/zero of=file1 count=195313
195313+0 records in
195313+0 records out
100000256 bytes (100 MB, 95 MiB) copied, 0.899838 s, 111 MB/s

real    0m0.924s
user    0m0.020s
sys     0m0.448s
$ time dd if=/dev/zero of=file2 bs=10MB count=10
10+0 records in
10+0 records out
100000000 bytes (100 MB, 95 MiB) copied, 0.172675 s, 579 MB/s

real    0m0.177s
user    0m0.004s
sys     0m0.172s