NVIDIA SATURN V Volta is a large GPU cluster operated by NVIDIA, located in the United States, in the private sector. It came online around November 2017. At that moment it ranked number 10 among known clusters.
It is built on 264 NVIDIA V100. That amounts to about 16.68 H100e of AI compute. The cluster draws roughly 0.19 MW. Its hardware is estimated at $5M.
Epoch AI rates the certainty of this record as confirmed. Seems likely that this cluster was folded into Saturn V Phase 2