Asus ROG says it is 'actively investigating' gaming laptop stuttering issues after a user apparently identified a 'cascade of firmware design failures'

I scour Reddit and support forums pretty regularly, and it's not exactly rare to see people complaining about systems or peripherals from specific brands. But it's often difficult to know whether those issues are widespread enough to designate a problem with those devices in particular. It doesn't seem like that's the case here, though, as Github user Zephkek seems to have found issues specifically with Asus laptop firmware (via Reddit).

I contacted Asus about this yesterday and am still waiting to hear back for more details, but in the meantime Asus ROG has released a statement on X explaining that its "team is actively investigating these cases." The "cases" in question are "performance interruptions on some ROG laptops," which Zephkek's Github analysis details.

It seems that some Asus ROG laptop owners have been experiencing stutters, freezes, and audio crackles. And apparently the problem is "embedded in the machine's firmware, the BIOS."

LatencyMon tests on different Asus ROG laptops showed that lag was being caused by ACPI.sys, but only on a single core. The investigator explains: "[ACPI.sys] primarily functions as an interpreter for ACPI Machine Language (AML), the code provided by the laptop's firmware (BIOS). If ACPI.sys is slow, it's because the firmware is feeding it inefficient or flawed AML code to execute."

They also noticed that these latency spikes are periodic, "occurring like clockwork every 30 to 60 seconds." And "a perfectly repeating pattern points to a systemic issue, a timer or a scheduled event baked into the system's logic."

So, they dug deeper and discovered a number of strange behaviours that are coded into, or as a result of, firmware. One is a high-priority interrupt that takes way too long to execute, another is the system repeatedly attempting to "power the discrete GPU on and off, even when it's supposed to be permanently active."

Zephkeh explains the problem simply:

1. "A hardware interrupt fires _GPE._L02.
2. The handler executes methods to check battery status.
3. Shortly thereafter, the firmware attempts to change the GPU's power state.
4. The system runs normally for about 30-60 seconds.
5. The cycle repeats."

The code for the "problematic GPE handler" that's responsible apparently "violates several fundamental principles of firmware and kernel programming." Sleep functions are used which can cause the CPU to stop processing, loops are used that are "capable of holding a CPU core hostage for potentially seconds at a time" and there's even a "self-rearming interrupt."

The investigation and analysis goes on, looking how this all links to other functions that cause the hang-ups thanks to battery polling and GPU notifications. Ultimately, the cause is laid at the feet of a "systemic design flaw" because in certain places the code is not "aware" of whether the system is in Optimux or Ultimate/Mux mode, ie, is not "aware" whether the iGPU is physically disconnected or not.

Crucially, "any firmware managing this hardware must be aware of which mode the system is in. Sending a command intended for one GPU to the other is futile and, in some cases, dangerous."

In many places the code recognises this, but according to Zephkek, "this perfect, platform-aware logic is completely abandoned in the critical code paths responsible for power management." This, in the end, results in a "cascade of firmware design failures" that results in periodic system interrupts.

I won't pretend to completely understand all of this, but that Asus ROG is actively investigating shows the claims at least warrants serious consideration. At any rate, all the code and methodology is there for us to scrutinise, if we wish.

Assuming the Redditor and Githubber here has identified the correct underlying cause, this might spell good news for some Asus ROG laptop gamers. Well, so long as it means updated firmware is released that fixes stuttering issues.