When increasing the Dbench client count from six to 48, the EXT4 and Btrfs file-systems pulled ahead.
Under the Seagate HDD, ReiserFS was the fastest file-system with the Flexible I/O Tester while the fastest with the OCZ SSD was XFS. EXT4 and Btrfs ran at close to the same speed on the HDD, but with the SSD, EXT4 was faster even though Btrfs has optimizations for solid-state drives.
EXT4, XFS, and JFS led the pact for the Threaded I/O Tester with 32 threads of 256MB random reads. On the solid-state drive, Btrfs was the slowest.