[marginalia_nu]

Did you dial up to run for 1 billion items?

In general I'm not a big fan of JMH for testing sustained I/O scenarios, as CPU, OS and storage behavior are extremely relevant, and JMH tends to interfere with access patterns.

[NovaX]

Nope, I used the default in your github repository (10_000_000). From a quick profile it looked like previous benchmark allocations where crossing into later runs, who were then penalized unfairly, so I made those small adjustments.