Estimated resources for a 500 connections instance (VM)

[David Gauthier <davegauthierpg@xxxxxxxxx>]

psql (9.6.0, server 11.3) on linux

We've ramped up usage on a PG server (a VM, I have no choice about this) and are approaching the 100 connections limit.  We could increase the limit, but I've read that this can lead to a degradation in performance. If we bump it up to 500, what kind of compute resources would that require (mem/cpu)?  Any estimates ?

Thanks !