Phoronix published a review on the EXT4 vs. XFS vs. Btrfs HDD Benchmarks On Linux 3.15
A quote from the article:
After earlier in the week delivering solid-state drive file-system benchmarks in comparing the Linux 3.15 FS performance to Linux 3.14 stable, now it's time to do a Linux 3.14 vs. 3.14 file-system performance comparison with a traditional hard drive. The file-systems being benchmarked here are EXT4, XFS, and Btrfs.EXT4 vs. XFS vs. Btrfs HDD Benchmarks On Linux 3.15 @ Phoronix