I have a laptop with an Intel Core i7-11800H, an 8-core/16-thread processor. Even when the system is idle, the CPU package seems to use around 4 watts. Since I rarely need all of the available performance, I'm considering disabling two cores so the processor runs with 6 cores and 12 threads while the others remain inactive. Would that meaningfully improve battery life? I have already limited the CPU to a 35-watt TDP, which is Intel's lowest official rating for this chip.
3 Answers
You could try reducing clock speeds or disabling Turbo Boost, though the battery-life improvement may be fairly small. Lowering screen brightness and using the operating system’s power-saving profile may have a larger effect, since the display and other components can consume significant power too.
Disabling a couple of cores may reduce power slightly, but modern processors already put unused cores into low-power sleep states. It’s worth testing, but disabling Turbo Boost or setting a lower maximum processor state may be more practical. The actual result will depend on what you do with the laptop and how much power the screen, graphics, and background devices use.
If you’re comfortable changing the operating system, a well-configured Linux installation can sometimes improve idle battery life, but it isn’t guaranteed. Power management settings, graphics drivers, and laptop firmware usually matter more than simply reducing the core count.
The 35-watt setting only applies to the CPU package; it doesn’t include power used by the display or the rest of the laptop.