ASUS ROG Gaming Laptops Affected by BIOS Firmware Issues Causing System Stuttering
Recent research published on GitHub by Zephkek, a cybersecurity specialist with a background in low-level programming, has uncovered persistent BIOS firmware issues in ASUS ROG gaming laptops. These firmware bugs are responsible for a range of system performance problems, including stuttering during YouTube playback, audio pops on Discord calls, brief mouse freezes, and other disruptive glitches. Contrary to common assumptions, these issues are not caused by pre-installed software, outdated drivers, or the operating system. Instead, the root cause lies deep within the ASUS BIOS firmware, which manages system-level operations and hardware components.
Investigating the Source of Stuttering on ASUS ROG Laptops
To diagnose the problem, the researcher utilized LatencyMon, a tool designed to measure CPU interrupt latency. Interrupt latency is a critical performance metric, as it reflects the time the CPU spends handling high-priority tasks that interrupt normal processing. On ASUS ROG laptops such as the Zephyrus M16, it was discovered that the first CPU core can spend over 90 seconds processing interrupts, effectively blocking it from performing other tasks. This leads to noticeable stuttering, especially when time-sensitive applications are running on that core.
The underlying issue is linked to the ACPI.sys driver, which implements the Advanced Configuration and Power Interface (ACPI) standard. ACPI.sys acts as a bridge between the system firmware and the operating system, managing power functions like sleep, hibernation, battery status, and thermal reporting, as well as facilitating Plug-and-Play device discovery. The driver interprets ACPI Machine Language (AML) code provided by BIOS manufacturers, including ASUS. Flaws in this implementation can result in inefficient interrupt handling and system instability.
User Reports and Firmware Updates
There have been mixed reports from users regarding the resolution of these issues. One TechPowerUp forum member, JustBenching, noted that a 2022 ASUS ROG Zephyrus G14 with an AMD Ryzen 7 6800HS and Radeon RX 6800S received a firmware update in early 2024 that appeared to resolve the stuttering. However, another user, SRB151, reported that a 2021 ASUS ROG Zephyrus G15 with an AMD Ryzen 9 5900HX and Radeon RX 6800M continued to experience stuttering, particularly after waking from sleep. These accounts suggest that the problem persists across multiple models and years, including the Strix, Scar, and Zephyrus series.
Power Management and MUX Switch Complications
ASUS ROG laptops typically feature both a discrete GPU (such as NVIDIA RTX 30/40 series) and an integrated GPU paired with the CPU. A multiplexer (MUX) switch allows the system to toggle between the iGPU and dGPU based on power requirements, such as running on battery or when connected to an external display. However, the research found that ASUS firmware is performing unnecessary and illogical power cycling of the dGPU. Even when the dGPU is the sole active graphics processor—such as when an external display is connected—the system continues to power the dGPU on and off every 15 to 30 seconds. This behavior is inefficient and can contribute to the observed stuttering and instability.
Root Causes and Ongoing Concerns
The investigation identified several root causes for these issues: misunderstanding of interrupt context, flawed interrupt handling, and a lack of platform checks that fail to account for the system's MUX mode. These problems have been documented in ASUS ROG laptops from 2021 through 2024, with multiple public reports confirming their persistence. As of the latest update, ASUS has not officially responded to the findings or addressed the documented firmware issues.
