It appears that the tester was actually running the chip on a standard PC in a
4-Way configuration.
For testing a 3D-Printed duct had to be made to deliver cooling to the card, since it comes with a passive heatsink which means there's no active cooling solution onboard the card.
It was not necessary to use a 4-way setup at least to test games, IMO. For display he had to use the GTX 1650 Ti graphics card as a secondary display card, since the H100 lacks display outputs.
If you watch the video carefully, it looks like using two H100s offered a 43% boost in content creation apps, but, 3-way and 4-way results showed diminishing returns and
negative scaling. Looks like standard PCs just can't take advantage of multiple H100 GPUs.