Phoronix has benchmarked ZFS on FreeBSD against EXT4 & Btrfs on Linux

ZFS is often looked upon as an advanced, superior file-system and one of the strong points of the Solaris/OpenSolaris platform while most feel that only recently has Linux been able to catch-up on the file-system front with EXT4 and the still-experimental Btrfs. ZFS is copy-on-write, self-healing with 256-bit checksums, supports compression, online pool growth, scales much better than the UFS file-system commonly used on BSD operating systems, supports snapshots, supports deduplication, and the list goes on for the features of this file-system developed by Sun Microsystems. In this article we are seeing how well the performance of the ZFS file-system under PC-BSD/FreeBSD 8.1 stacks up to UFS (including UFS+J and UFS+S) and on the Linux side with EXT4 and Btrfs.

  Benchmarking ZFS On FreeBSD vs. EXT4 & Btrfs On Linux