We didn't configure any parameters for password hashing. We use the default settings, Argon2.

No headroom given as we state in the blog: Because our test used a constant load, we did not allocate as much CPU as we typically recommend. We strongly recommend leaving 150% extra headroom for CPU usage to handle spikes in load, as mentioned in our documentation.
Both logins and refreshes happen concurrently.

Hi @wfouche, thank you for your comment. See answers below.

How long can performance be sustained at the high throughput rates that are mentioned in the benchmark report?

I'm unsure how to answer or measure this. Have you observed some problems in your deployment?

The worst response observed should ideally also be reported; just mentioning percentiles is not enough.

Most SLOs are defined in percentiles (at least, the ones that cross my hands). Here is the KC 26.4 report:

What is the $ cost per unit of throughout?

We did some cost analysis last year, and you can see it here: keycloak/keycloak-benchmark#1022 (comment)
For AWS, the Graviton processor is the most cost-effective. For other cloud providers, I'm afraid I can't get that information.

@pruivo , thank you for your response. I have a general interest in benchmarking and how benchmark results are reported. Always learning.