Our initial file-system testing of EXT4, XFS, Btrfs, and F2FS from the Linux 3.13 kernel appear to reveal that the performance overall is slower than when using the Linux 3.12 kernel on the same software/hardware configuration.
For reasons yet to be determined, the F2FS, XFS, EXT4, and Btrfs file-systems appeared on average to be slower with the latest Git kernel of the Linux 3.13 kernel compared to the Linux 3.12 kernel. This initial testing was done using a Serial ATA 2.0 solid-state drive while tests are in the process of being carried out from a traditional hard drive. The file-system mount options hadn't changed between running the different kernel versions and the kernels themselves were obtained from the Ubuntu Mainline Kernel PPA.
The EXT4, Btrfs, XFS, and F2FS file-systems were tested on an Intel Core i5 3470 "Ivy Bridge" system with ASRock Z68 Pro3 motherboard and 64GB OCZ SATA2 SSD. All benchmarking was handled via the Phoronix Test Suite. On the following pages are the worrisome file-system results.