We’re recently running two machines (master and standby) at M5 Hosting. All of HN runs on a single box, nothing exotic:
CPU: Intel(R) Xeon(R) CPU E5-2637 v4 @ 3.50GHz (3500.07-MHz K8-class CPU)
FreeBSD/SMP: 2 package(s) x 4 core(s) x 2 hardware threads
Mirrored SSDs for data, mirrored magnetic for logs (UFS)