M2 MacBook Air aggressively throttles P-cores based on a non-CPU sensor, even when CPU is cool

I'm running a MacBook Air M2 on **macOS Tahoe Beta 26.0 (developer beta 4, 25A5316i)** and have noticed a peculiar and aggressive thermal throttling behavior that makes the system very slow under sustained load. **The Problem:** When the machine's case gets hot, the system seems to enter a heavily throttled state. My monitoring app (Stats) shows that all **Performance cores are effectively shut down**: their utilization drops to 0% and their frequency is locked at the lowest state (660 MHz). This forces all system processes onto the **Efficiency cores**, which then run at 100% load. The computer becomes extremely sluggish and borderline unusable for anything beyond basic operations like text editing. Here is a screenshot of the system in this throttled state (Image 1): As you can see: * P-cores are at 0% usage and 660 MHz. * E-cores are at 100% usage. * The Average load is extremely high (68.48 over 1 minute). **The Paradox: It's Not Directly Tied to CPU Core Temperature** My initial assumption was that this was standard CPU thermal throttling. However, my observations show this is not the case. The throttling seems to be triggered by a different thermal sensor, not the CPU cores themselves. **Evidence 1: Throttling Occurs at Low CPU Temperatures** Here is a sensor reading from when the machine was in the throttled state described above. > Note: I don't know why the Stats app shows all cores as 'performance core' in this tab. * **Average CPU temperature is only 59.3°C**, and the hottest core is 61.2°C. These are very safe temperatures. * Despite the cool CPU, the P-cores are shut down as shown in the first image. **Evidence 2: No Throttling Occurs at High CPU Temperatures** Conversely, I can push the CPU to its thermal limit (e.g., with a short, intense task) without triggering this specific P-core shutdown, as long as the machine's chassis hasn't had time to heat soak. * Here, the **CPU cores are running at over 100°C** while the machine was still not throttled. * The CPU Power draw is high (14.53W) compared to the throttled state (0.16W), indicating the P-cores are active. * The system remains responsive during this time. This leads me to believe the throttling is a proactive measure based on a chassis, battery, or other component's temperature, rather than a reactive measure to the CPU's own temperature. **My Questions:** 1. What is the specific thermal management mechanism at play here? Is it a known behavior for fanless MacBooks to shut down P-cores? 2. Could this be a bug or an overly aggressive policy, possibly related to the macOS developer beta I am running? 3. Is there any way to adjust or disable this specific, preemptive throttling behavior? I understand the need for thermal management, but the current implementation makes the machine unusable long before the CPU itself is in any thermal danger.