Linux 3.3 Kernel: Btrfs vs. EXT4
After upping the FS-Mark test to 5000 files of 1MB size and using four threads, EXT4 was faster on both systems. It was also faster with 4000 files of 1MB size spread across 32 sub-directories.
When running IOzone with an 8GB write test of 4Kb block sizes, EXT4 was faster than Btrfs on the Core i3 330M while the Core i7 720QM edged slightly ahead with Btrfs.
When looking at the IOzone 8GB read performance, EXT4 was faster on both systems with the Linux 3.3 kernel.