Hello all.
I'm faced to the same problem.
I'm using 240GB 530-series for MySQL database on Linux (yes, I know that it's not the best idea to use it for MySQL, but I had the only option at that time).
My NAND writes was 2.6 times bigger than Host writes.
Searching on the internet gave me nothing, except one link in intel community russian branch https://ru.intel.com/business/community/?showtopic=9283
They discovered that the problem is in DevSleep function introduced in new revision of SF-2281 controller. Device is going to energy saving mode too often, and it writes down it's cache to NAND every time it going to that mode.
I wrote a small bash script that reads a small file 8 times per second in infinite loop:
#!/bin/bash
while true
do
dd if=/var/lib/mysql/readme of=/dev/null bs=512 count=1 iflag=direct
sleep 0.125
done
And it really works! While script is running, NAND writes dramatically decreased, and now I have total NAND writes only 1.6 times bigger than host writes.
In addition, the latency also decreased more than twice.
I wonder, is there any way to completely disable DevSleep?