[ ... ] I now found out that performance of a 520s SSD is
around 180 times faster than a 530s SSD. [ ... ]
Well "performance" can be roughly the same, even if "speed" can
be very different.
http://www.sabi.co.uk/blog/15-two.html#151023
520s: 70MB/s
530s: 0.4MB/s
....
fio --filename=/dev/sdb --direct=1 --sync=1 --rw=write --bs=4k
--iodepth=1 --runtime=60 --time_based --group_reporting
--name=IntelDC3510_4kj1 --numjobs=1
Arguably the 520s actually have no performance.
https://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/