When using 12 clients with Dbench, the EXT3 file-system had sustained 34.69MB/s, EXT4 was at 32.57MB/s, and Btrfs was at 21.66MB/s. XFS was the slowest here at 13.95MB/s
Upping the client count to 128 had allowed Btrfs to end out today's testing on top. The EXT3 files-system was at 20.39MB/s, EXT4 at 36.71 MB/s, XFS at 7.31MB/s, and Btrfs at 38.61MB/s.
Well, Btrfs is not yet the performance king of Linux file-systems. In fact, in a majority of our tests, the EXT4 file-system had actually outperformed Btrfs by a significant margin. The XFS file-system also did better than Btrfs at some of these disk performance tests. It also took slightly longer to boot the system when using Btrfs over EXT3/EXT4. To reiterate, however, all settings each time were left at their defaults. With our initial Btrfs tests we simply ran each file-system with the standard Fedora file-system defaults and system settings and the latest release of Btrfs in the Linux 2.6.29 kernel.
In the near future we will deliver more benchmarks as we look at what Btrfs mount options may improve the performance for this Better FS along with using the latest bits from the Linux 2.6.30 kernel. We will also be exploring the SSD optimizations within the Btrfs file-system.
While Btrfs does not conclusively have a performance advantage at this point, it does have advanced features for a Linux file-system like snapshots, check-summing, online defragmentation, etc. It is also important to keep in mind that Btrfs continues to undergo heavy development and its on-disk format is not necessarily stabilized at this point. Over the next several Linux kernel releases we should hopefully see Btrfs stabilize.
If you would like to reproduce these results yourself, install the latest development release of Fedora 11 and then run yum install phoronix-test-suite followed by phoronix-test-suite benchmark filesystem. It's as easy as that! The Phoronix Test Suite will take care of downloading all relevant tests, installing the tests locally, and then carrying out the tests in an automated and standardized fashion. The Phoronix Test Suite also generally runs each test multiple times in order to ensure the results are statistically significant and accurate. If you would like to run the Dbench test profile and use the newer features, you will need to checkout the latest Phoronix Test Suite 2.0 "Sandtorg" code from Phorogit.
More information on our open-source performance profiling and benchmarking software is available at Phoronix-Test-Suite.com.