Reduce the number of CPU cores when using battery power.
Reduce the number of CPU cores when using battery power.
I recently purchased a Dell G7 7590 equipped with an i7-9750H processor. Running it on AC is quite powerful, but using it on battery mode causes noticeable slowdowns with certain applications and older games. This behavior is similar to what I experienced with a budget A12 APU notebook, where battery performance deteriorated significantly compared to the same hardware running on a more expensive system. Based on my limited testing, it appears the issue stems from power delivery constraints imposed by the battery, which limits CPU performance per core as more cores are active. For instance, when only one core is running (as shown in Intel's XTU), its speed drops to just under 3GHz, while apps like Firefox operate smoothly with all six cores at around 1GHz or less. You're looking for a solution that automatically caps the system to four cores during battery use, maintaining full performance on AC without requiring frequent BIOS reboots. This would help preserve core speed for your workloads while still benefiting from all six cores when charging.
Check out ThrottleStop. It's a tool that manages power, voltage, and clock speed. You can create profiles for battery or AC power and it will switch on its own. You can't change the core count, but you can tweak settings to reduce throttling (depends on CPU and model). I use it on a Thinkpad T540p to handle the automatic throttling caused by the third-party battery I have.
After thorough investigation and testing, it appears Dell embedded throttling directly into the firmware. Regardless of adjustments in Windows or ThrottleStop, the battery performance remains affected.