Meta Research SuperCluster (RSC-1) Phase 2 is a large GPU cluster operated by Meta AI, located in the United States, in the private sector. It came online around May 2023. At that moment it ranked number 4 among known clusters.
It is built on 16,000 NVIDIA A100. That amounts to about 5K H100e of AI compute. The cluster draws roughly 13.28 MW. Its hardware is estimated at $357M.
Epoch AI rates the certainty of this record as confirmed. The location is found from triangulating from the promo video. I'm fairly confident in it, but it isn't guaranteed to be accurate