random_page_cost and effective_io_concurrency are hardcoded to SSD values

[jflambert]

Using pgtune, I get random_page_cost/effective_io_concurrency recommendations of 1.1/200 for SSD and 4/2 for HDD. I see these recommendations in other tools or websites as well.

timescaledb-tune hardcodes its recommendations to 1.1/200 (SSD)

How important is it for these two settings to be set according to your drive type?

[matthock]

I'm going to second this issue based on behavior I've seen in my own environment. It works fine when operating on an SSD, but when operating on a magnetic drive or a raid array thereof, the system will completely grind to a halt with relatively small amounts of data (200-300mb), resulting in several second query latency as psql spikes cores to 100% (for context, this is using the timescaledb docker container which is automatically running timescaledb-tune on initialization). When I go in to the configuration and hand change these values to what pgtune would recommend for the drives, the CPU usage drops to single digits and the queries become nearly instantaneous. The rest of the tuning seems fine, but these particular values will absolutely destroy performance on a magnetic drive.