[denshi_karasu]

Yes and no. I have all sorts of test results for the 4.x kernel, but they are for i3 instances rather than i2.*, so they wouldn't be directly comparable. Your question kind of makes me think I should put together an updated version of this talk; I've gathered enough material over the last couple of years that would probably be useful to somebody.

[robinanil]

Yes, that would be useful. 4.x kernels has some block io improvements and some recent phoronix benchmark shows ext4 making huge strides.