IO from dd if=/dev/zero
CPU utilization from "time -f%P"

Raw Device
==========

buffered 1M IO
4294967296 bytes (4.3 GB) copied, 82.8985 s, 51.8 MB/s
4294967296 bytes (4.3 GB) copied, 82.7046 s, 51.9 MB/s
CPU: 12%

direct 1M IO
4294967296 bytes (4.3 GB) copied, 81.8457 s, 52.5 MB/s
4294967296 bytes (4.3 GB) copied, 81.8476 s, 52.5 MB/s
CPU: 2%

buffered 4k IO
4294967296 bytes (4.3 GB) copied, 82.8577 s, 51.8 MB/s
4294967296 bytes (4.3 GB) copied, 82.7146 s, 51.9 MB/s
CPU: 13%

direct 4k IO
4294967296 bytes (4.3 GB) copied, 258.710 s, 16.6 MB/s
4294967296 bytes (4.3 GB) copied, 258.719 s, 16.6 MB/s
CPU: 23%

ext3 filesystem
===============

buffered 1M IO
4294967296 bytes (4.3 GB) copied, 95.3044 s, 45.1 MB/s
4294967296 bytes (4.3 GB) copied, 97.2934 s, 44.1 MB/s
CPU: 10%

direct 1M IO
4294967296 bytes (4.3 GB) copied, 99.6338 s, 43.1 MB/s
4294967296 bytes (4.3 GB) copied, 97.8586 s, 43.9 MB/s
CPU: 2%

buffered 4k IO
4294967296 bytes (4.3 GB) copied, 99.9704 s, 43.0 MB/s
4294967296 bytes (4.3 GB) copied, 98.9158 s, 43.4 MB/s
CPU: 12%

direct 4k IO
4294967296 bytes (4.3 GB) copied, 412.590 s, 10.4 MB/s
4294967296 bytes (4.3 GB) copied, 411.362 s, 10.4 MB/s
CPU: 17%

ext4 filesystem
===============

buffered 1M IO
4294967296 bytes (4.3 GB) copied, 81.6657 s, 52.6 MB/s
4294967296 bytes (4.3 GB) copied, 81.1585 s, 52.9 MB/s
CPU: 13%

direct 1M IO
4294967296 bytes (4.3 GB) copied, 84.0730 s, 51.1 MB/s
4294967296 bytes (4.3 GB) copied, 84.3677 s, 50.9 MB/s
CPU: 2%

buffered 4k IO
4294967296 bytes (4.3 GB) copied, 83.1531 s, 51.7 MB/s
4294967296 bytes (4.3 GB) copied, 81.5240 s, 52.7 MB/s
CPU: 16%

direct 4k IO
4294967296 bytes (4.3 GB) copied, 347.121 s, 12.4 MB/s
4294967296 bytes (4.3 GB) copied, 381.056 s, 11.3 MB/s
CPU: 19%


xfs filesystem
==============

buffered 1M IO
4294967296 bytes (4.3 GB) copied, 78.8623 s, 54.5 MB/s
4294967296 bytes (4.3 GB) copied, 78.5457 s, 54.7 MB/s
CPU: 9%

direct 1M IO
4294967296 bytes (4.3 GB) copied, 89.9843 s, 47.7 MB/s
4294967296 bytes (4.3 GB) copied, 89.8178 s, 47.8 MB/s
CPU: 2%

buffered 4k IO
4294967296 bytes (4.3 GB) copied, 83.2343 s, 51.6 MB/s
4294967296 bytes (4.3 GB) copied, 81.9343 s, 52.4 MB/s
CPU: 11%

direct 4k IO
4294967296 bytes (4.3 GB) copied, 1221.78 s, 3.5 MB/s
4294967296 bytes (4.3 GB) copied, 1221.40 s, 3.5 MB/s
CPU: 6%