More cores or more Ghz?

We have an InfluxDB containing more 1.1million series. Writes per second are very low. We also do few queries.
But the queries we do are pretty big and have to cover and analyze lots of data. Same for our CQ. Few, but cover lots of data.

I am thinking of moving to a new server but I have the option to get 12 cores 3.5Ghz or 40+cores 2.4Ghz or even 2.1Ghz.

So I am curious what would better in our case. When running 1 large query, is it using only 1 core or it will be able to use all 40 cores and finish even faster?

I didnt find any benchmarks of Influx performance on different kind of hardware. And the benchmarks that exist focus mostly on writes/sec that we dont care about.

In general, I would go with more cores. We use multiple cores when possible for writes, compactions, and queries. For queries, it does depend on the shape of the data and what kind of query is running, but we do try to parallelize things when we can.

I would also recommend that you use directly attached SSDs and as much RAM as you can. Since we memory map TSM files on disk, the OS page cache will use free memory to serve them from RAM.

If you are able to test on similar hardware before you make a decision, that would probably give you the most definitive answer though.

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First you should make sure if the bottleneck is the CPU at all. Maybe you don’t need more GHz or more cores, you need more RAM or faster storage. Does the CPU get to 100% while running queries?

Edit: sorry, I’m new to this forum and I didn’t realize how old this thread was :sweat:


No problem! Thank you for contributing!