AIST ABCI 1.0 is a large GPU cluster operated by National Institute of Advanced Industrial Science and Technology (AIST), located in Japan, in the public sector. It came online around June 2018. At that moment it ranked number 5 among known clusters.
It is built on 4,352 NVIDIA Tesla V100 SXM2. That amounts to about 275 H100e of AI compute. The cluster draws roughly 2.99 MW. Its hardware is estimated at $177M.
Epoch AI rates the certainty of this record as confirmed.