## Problem
In Neon DBaaS we adjust the shared_buffers to the size of the compute,
or better described we adjust the max number of connections to the
compute size and we adjust the shared_buffers size to the number of max
connections according to about the following sizes
`2 CU: 225mb; 4 CU: 450mb; 8 CU: 900mb`
[see](877e33b428/goapp/controlplane/internal/pkg/compute/computespec/pg_settings.go (L405))
## Summary of changes
We should run perf unit tests with settings that is realistic for a
paying customer and select 8 CU as the reference for those tests.
