I'm using 4 512GB Samsung 850 EVOs in a hardware RAID 10 on a 1U server with about 144 GB RAM and 8 Xeon cores. I usually burn up CPU more than I burn up disks or RAM as compared to using magnetic where I had horrible IO wait percentages, so it seems to be performing quite well so far.
One of our four "big iron" (spinning disks) servers went belly up today. (Thanks, Postgres and pgbackrest! Easy recovery.) We're planning to move to a cloud service at the end of the year, so bad timing on this. We didn't want to buy any more hardware, but now it looks like we have to.
I followed the discussions about SSD drives when they were first becoming mainstream; at that time, the Intel devices were king. Can anyone recommend what's a good SSD configuration these days? I don't think we want to buy a new server with spinning disks.
We're replacing:
8 core (Intel)
48GB memory
12-drive 7200 RPM 500GB
RAID1 (2 disks, OS and WAL log)
RAID10 (8 disks, postgres data dir)
2 spares
Ubuntu 16.04
Postgres 9.6
The current system peaks at about 7000 TPS from pgbench.
Our system is a mix of non-transactional searching (customers) and transactional data loading (us).