File-Systems Appear To Slowdown On Linux 3.13 Kernel
Phoronix: File-Systems Appear To Slowdown On Linux 3.13 Kernel
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.
13.3 has been verified for Ubuntu LTS 14.04 ... so this will get some quick attention
That being said, those are some pretty harsh regressions for any kernel status.
Would be very interesting to see how spinning storage does.
As the most simple inquiry ... can you see how many cores are being utilized for IO? As alluded to by Marco, there's changes afoot to spread IO across cores. Perhaps that's where the train's leaving the tracks?
BTRFS was supposed to have a big jump in performance so what we might be seeing is a roughly equal performance hit, with BTRFS performance increases masking some of the IO performance decreases.