The “nameplate” power rating of a chip, often based on its thermal design power (TDP), reflects the maximum theoretical power it could draw under extreme, fully saturated workloads. These ratings are used to inform the electrical system design, but in practice, chips rarely operate near those levels. Reaching 100% of nameplate power across an entire rack or cluster is not only unusual, it's extremely difficult to sustain, and often not desirable given reliability and thermal constraints.
This is why you can’t just multiply the no. Of chips by their max TDP to work out energy usage in a given period