How much can Core Ultra 9 290HX Plus's performance change between power modes, and when should performance mode be used?

  Mode scaling on the 290HX Plus follows sustained CPU power, shared GPU TGP, and cooling. Processor Base Power is a rated figure, not measured all-core consumption.

  To verify: plug in and run the same compile, render, or game scene for 15–20 minutes in balanced and performance modes, logging CPU/GPU power and clocks. If performance mode gains under ~5%, use balanced; if it gains more but clocks later fall by over ~10%, the chassis cooling or power wall is the limit. Short bursts don't represent sustained performance.