It is also important for the 'count=' option. You specify the count in terms of 'bs'. So 'bs=1M count=1000' would write 1000 M in 1M chunks.
Also, a higher 'bs' usually leads to better performance. From my benchmarks 'bs=4M' or 'bs=6M' work best depending on your processor cache size and other factors.
Last edited by metaschima; 06-14-2014 at 12:09 PM.