The Asus Gaming Laptop ACPI Firmware Bug: A Deep Technical Investigation
9 hours ago
- #Performance
- #Firmware
- #ASUS
- High-end ASUS ROG laptops experience stuttering and audio issues due to firmware-level problems.
- Conventional fixes like driver updates and OS reinstallation fail to resolve the issues.
- LatencyMon identifies ACPI.sys as the source of high interrupt-to-process latency.
- ACPI.sys inefficiencies stem from flawed ACPI Machine Language (AML) code in the BIOS.
- Event Tracing for Windows (ETW) reveals periodic spikes in ACPI.sys activity every 30-60 seconds.
- Firmware incorrectly attempts to power cycle the discrete GPU in MUX mode, causing system instability.
- Decompiled ACPI code shows sleep calls within interrupt handlers, violating kernel programming principles.
- The firmware fails to check MUX mode before sending GPU power commands, leading to unnecessary power cycles.
- The issue is systemic across ASUS gaming laptops from 2021 to present, affecting multiple models.
- User reports and traces confirm the problem persists despite BIOS updates and hardware changes.