Hello,

i run a few performance tests comparing mdadm, hardware raid and the btrfs raid. I noticed that the performance for small blocksizes (2k) is very bad on SSD in general and on HDD for sequential writing.
I wonder about that result, because you say on the wiki that btrfs is very effective for small files. 

I attached my results from raid 1 random write HDD (rH1), SSD (rS1) and from sequential write HDD (sH1), SSD (sS1)

Hopefully you have an explanation for that.

raid@raid-PowerEdge-T630:~$ uname -a
Linux raid-PowerEdge-T630 4.10.0-33-generic #37~16.04.1-Ubuntu SMP Fri Aug 11 14:07:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
raid@raid-PowerEdge-T630:~$ btrfs --version
btrfs-progs v4.4


best regards

Carsten