Benchmarks: File Copy Performance
It appears that BTRFS must be quicker than EXT4 when reading data, as the copy performance which is obviously a mix of read and write performance, has the DS216+ armed with BTRFS well ahead of its EXT4 configuration when working with large files.
Oddly the DS216+ was faster than the DS716+ in this test with the pair using BTRFS, though keep in mind the DS216+ was tested using a more up to date version of the DSM.
Again the DS216+ proves to be exceptionally fast, this time in our game copy test using BTRFS in a RAID1 configuration it sustained 65MB/s while the DS716+ managed 58MB/s.
Finally, we have the program copy test and here the DS716+ and DS216+ provided the exact same result, which is more in line with what we were expecting to see. A throughput of 30MB/s makes these the quickest two-bay NAS devices we've tested.