Or have them set up in a way that makes them hard to run full-system benchmarks on. I can think of a couple of financial firms that have clusters that would rate on the Top 10, but a) as you suspected, they’re too busy running the money printers to take them down for a few days to run benchmarks, and b) they’re split up into more manageable little clusters, so the high speed fabrics don’t connect and allow every node to talk to every other node, which you need for an HPL run.