The Asus Gaming Laptop ACPI Firmware Bug: A Deep Technical Investigation

119 signa11 55 9/17/2025, 3:54:36 AM github.com ↗

Comments (55)

fulafel · 1h ago
Impressive that they managed to ship crippling stuttering for 4 years in gaming laptops specifically. Makes you wonder about the end user psychology, evidently they didn't get a show stopping rate of product returns.

A quote from one of the linked reddit threads. I wonder if the warranty trip is part of their scheme.

"I did everything you suggested , but nothing changed. I send it back via garante. I am curious what they do whit it."

"what was it at the end? did they respond?"

"They have claimed that the plato works perfectly. So basically i just got use to it. I am using bluetooth earbuds all the time so i cant notice the problems."

nodja · 11m ago
I've owned 2 gaming laptops in my lifetime and both had similar issues that were never fixed.

One was the first gen Alienware M17 with two GTX 270M GPUs (yes two) and an onboard nvidia GPU whose specific model I can't remember. That one suffered from stutters and audio crackling, etc. It was sort of fixed by disabling SLI and the onboard GPU and sticking to a specific driver that was modded, the driver was by someone on the notebookcheck forums IIRC. Later on I think it got somewhat patched with a bios update that let you use SLI without the stutters, but I think the laptop reached EOL without it being fully fixed.

The second was an ROG ASUS laptop with a GTX 460m (I can't recall the laptop model). Pretty much the same story as the OP but I didn't have the knowhow to go deep into the ACPI code. The only change from the story is that latencymon kept attributing the latency spikes to multiple dlls, sometimes it was some wifi driver, other times it was an nvidia one. I don't remember the full fix for that one, but it involved me changing the wifi card and disabling the dGPU (not the onboard one) when I was not gaming so I could watch videos and such without it crackling. Funnily enough it didn't crackle much when actually playing games (it still happened, just very rarely).

I stopped buying gaming laptops after that. Seeing this story makes me think things haven't changed one bit.

pjmlp · 1h ago
That is what happens when the industry has spent decades educating users that is normal computers are broken.

In any other industry everyone would be returning their acquisitions day one.

About 35 years ago, I had a teacher asserting computers are like buying shoes that randomly explode when tying them.

Thankfully consumer laws are finally happening.

SchemaLoad · 1h ago
Windows laptop users are just conditioned to the fact that they don't work properly and just deal with the issues.
pjmlp · 38m ago
As if Apple land was free of issues, remember those wonderful keyboards, Snow Leopard, Tahoe among many other examples, or any Linux laptop for that matter.
IlikeKitties · 59m ago
I don't see Mac or Linux Laptops being that much different in that regard.
CrossVR · 45m ago
My 2013 Macbook also had a display mux that switched the laptop display itself between the integrated and discrete GPU. In some cases it would fail to properly switch the display over causing it to remain permanently off until the next reboot. I was not the only Macbook user with the problem.

Apple is just as guilty for shipping laptops with hardware issues that you just have to work around. And unlike this Asus issue the Macbook mux was on by default. You had to turn it off in the settings if you wanted to entirely avoid the issue and then you would have no way of using the discrete GPU.

CrossVR · 53m ago
This flaw only happens in Ultimate mode, when the user explicitly tells the mux to switch to the discrete GPU. This is an extra feature only users who primarily use the laptop for gaming with an external display care about.

The laptop works fine in Optimus mode even with external displays, you just lost a bit of performance and you're missing out on some display features like G-Sync. So it is highly likely that most users always use the laptop in Optimus mode. If you primarily use the laptop as a laptop you probably wouldn't even know the mux feature existed.

The problem is Asus shipping extra features in their hardware that are not properly QA tested. It looks like they only thoroughly tested the golden path.

Strom · 43s ago
Asus doesn't even test basic features, nevermind the extra ones. I have the 2017 Zephyrus GX501, which came with a Nvidia GTX 1080 which introduced HDMI 2.0 support. The Asus Zephyrus marketing material is boasting about HDMI 2.0 capability, the manual talks about HDMI 2.0 etc. However, in reality the device is limited to HDMI 1.4 bandwidth.

The problem isn't limited to some units, there was plenty of discussion online of this issue at the time of release. [1]

Asus never recalled, fixed, or even responded to the issue. Indeed, even the marketing page [2] still talks about how you can use HDMI 2.0 to connect 4K TVs at 60Hz.

It was also an interesting showcase of laptop reviewer incompetence. All the reviews just regurgitated Asus marketing material on how it has HDMI 2.0, but apparently nobody actually tested it.

--

[1] https://rog-forum.asus.com/t5/rog-zephyrus-series/gx501-zeph...

[2] https://rog.asus.com/laptops/rog-zephyrus/rog-zephyrus-gx501...

fulafel · 14m ago
Seems to me this can't be concluded from the information at hand. This investigation used the mode, but the linked reddit posts I read complaining about ACPI latencies reportedby latencymon don't mention it.
immibis · 58m ago
All the evidence points to corporations, in general, not caring about making products that actually work.
unwind · 40m ago
This is an amazing discovery, article, and fix. Fantastic work, very impressive and also very instructive on how things work on modern PCs and how far you can actually dig to get at stuff that is "supposed" to be hidden.

As someone who has written embedded firmware for many years (not for PCs), I can only dream of an end user being this capable to discover a bug. I want to live in the world where Asus immediately send an e-mail offering some kind of short-term contracting work to fly in and talk to their firmware people for a few days and get $FIVE_FIGURES or something, and leave with an updated laptop running their new production BIOS.

Obviously this bug has gone un-fixed for four years so that is not the world we're in. That makes me sad. :|

userbinator · 1h ago
I wonder if the "programmer" (and I use this term very loosely) who wrote that sleep-in-an-interrupt code ever tested the code personally, or if it was some other distant responsibility-diluted department of a hundred other lamers who didn't care "because the automated tests all pass". This is a situation where dogfooding, in the original Microsoft sense, would definitely be beneficial as among the developers experiencing this on their own machines, surely one would be tempted to fix it.
Animats · 1h ago
Short version: don't buy ASUS gaming laptops until this is definiteively fixed, and if you one under warranty, file a warranty claim, being prepared to go to Small Claims Court.
izacus · 13m ago
Most other laptops don't even have the mode you need to put the ASUS in to get this bug.

I don't think I ever put any of my laptops into dGPU-only mode via MUX, it's stupidly power hungry with little upside.

frnx · 2h ago
I have an older ASUS laptop from 2015 which also has (more minor than this!) ACPI state management bugs. I initially bought that machine because it was a pretty high-end and was somewhat disappointed about both the build quality and the firmware/software support.
kingstnap · 1h ago
Somehow laptop makers all write complete garbage firmware.

I'm sure dell does the same terrible handling of DGPU power and badly written ISRs that pointless raise system latency. I had shoddy crashes for months that would cause my dell laptop to BSOD and burn up in my backpack because the DGPU got stuck on I a loop during some ridiculous windows modern standby wakeup.

SchemaLoad · 1h ago
Only devices I've had which seem to work flawless are macbooks and the steam deck. The ability to properly suspend and wake without issue is so rare.
jeroenhd · 1h ago
I was pretty disappointed when my work MacBook ran into the same "Bluetooth headset connected, set as audio sink, but the OS refuses to acknowledge its existence further and routes audio through the speakers" but that I've seen on every other desktop OS. I really hoped Apple would be better, considering their hardware costs more than twice as much.

I also ran into weird Wi-Fi issues that required a reboot, and getting that thing to recognize external displays without corrupting video is some kind of dark art while my Lenovo and Steam Deck work just fine with the same USB C plug.

Apple beats some brands for sure (especially the cheap "consumer" lines with a starting price lower than Apple's headphones) but their computers are hardly flawless.

I have yet to run into issues with my Steam Deck, which is very impressive, but I'm sure I'll run into an issue at some point. No computer works flawlessly.

argsnd · 21m ago
Did you have these issues on Apple Silicon MacBooks? I ask because they seem to have very different networking and display stacks.
hypercube33 · 1h ago
Surface Pro 8s have a bug where the battery just gives up randomly and won't ever charge again. 2, 3,4 and 7 do not have this - one sitting on my shelf two years charged right up from 10%.

Replacing the battery costs like $200-500 because the screen likes to explode when removing it.

Lenovo docks of a specific gen will have the USB hub/billboard just crash and stop doing display port.

older Dell docks would pollute arp tables and crash switches.

Computers have always had some wild flaws, some worse than others. They are built to a price point typically and by humans under politics so the best design or parts usually don't make it -- cost and profit.

Panzer04 · 2h ago
No wonder people end up pushing macs.

It's unbelievable that something this bad has been shipping for four years. I guess I know what I'm not buying, at least...

jsiepkes · 2h ago
Apple also had issues like these. For example this one where it also first denied the issue: https://9to5mac.com/2019/10/24/efi-firmware/
toast0 · 57m ago
I had a mac at work for 8 years. Overall things mostly worked ok, but I had two big issues.

a) one time charging stopped working... thankfully I had a pretty full charge when I noticed and was able to migrate my data to a spare machine and not have to deal with it... removable storage would have been super handy.

b) for a whole year, there was about a 25% chance of loud static instead of music when I started playing a stream in iTunes; pause and play again would fix it most of the time. It started when I installed a named OS revision, and it stopped when I installed the next version. Did not have issues with sounds from other apps. Of course, there was no information to be found anywhere about this, because 'macs just work'

Less big, but if Outlook was running when I put the laptop to sleep, there was a good chance it would continue to eat battery and generate heat in my bag. Outlook is a travesty, but when the corp runs Exchange, Outlook is less effort to make work compared to fighting to make auth work with anything else and then still having to use Outlook from time to time.

pjmlp · 1h ago
They have their own issues as well, for those of us outside the distortion field.
bzzzt · 14m ago
The big difference is Apple can't hold other companies accountable since they delivered the software, the hardware and the integration and they have an incentive to fix their stuff. The few issues I've had with Macs the last decade did get fixed within a reasonable amount of time. Lots of PC hardware bugs simply don't get fixed at all since there is no party that really cares about them. The author of the linked write-up should have been an Asus employee instead of a disgruntled user...
SchemaLoad · 2h ago
Reminds me of when MSI laptops were getting properly bricked after users ran `rm -rf /` because of a UEFI bug where the board could not boot after some variables got deleted https://github.com/systemd/systemd/issues/2402
brian-armstrong · 1h ago
Excellent sleuthing. I feel like this has some great quick debugging ideas for system wonkiness that I never knew existed.

It feels a bit of a shame to wrap it all up in an AI-written summary, but I guess if that was the only way to get the info out, so be it.

thrdbndndn · 1h ago
Excellent article.

I do not have the same technical depth to dig this far as the author, but this kind of problem seems pretty common on laptops, especially those with "switchable" iGPU/dGPU setups.

I had an Acer laptop about 7-8 years ago with almost the exact same latency symptoms. In the end I just disabled the dGPU in the BIOS (since I only used it for office work), and that instantly solved the issue.

This kind of thing is very infuriating because not only is it hard to track down the root cause (which I am very grateful the author did), but it is also even harder to get the vendor to actually acknowledge or fix it.

hypercube33 · 1h ago
Intel laptops with igpu and Nvidia chips and thunderbolt docks are absolutely a nightmare between the 3 trips video has to go to even leave the laptop and the drivers and firmware mismatches.

I've had weird issues with this setup since the core2duo days upgrading once a year.

when it works it's amazing, however.

AMD igpu and dgpu work super well together but I feel like over time, since I use this configuration the most things either improve or go to hell with driver updates. depends on the laptop OEM really.

This all said, where the hell are the strix points igpus where they rival desktop cards (yes the lower mid end) at laptops where stuff just works without compromise ...if there is power and cooling.

Side note - I have a rog g14 that until I loaded a beta bios for thunderbolt over usb4 would reboot when shut down and shut down randomly. (amd CPU and GPU)

dlcarrier · 3h ago
One laptop model with buggy ACPI down, 5,387 to go.
orbital-decay · 2h ago
It says it affects all ASUS laptops since 2021, making them stutter at the most basic tasks.

Which I'm ready to believe, knowing the state of most laptops... but this entire thing is pretty clearly generated by Gemini with its over-the-top dramatic style, italics emphasis, and -isms like "It's not just X, it's Y", which was unable to handle the article of this size and started looping over. Not sure I should believe any of it, or at least be sure that it didn't mess up the specifics. Why would one do this in a technical writeup?

immibis · 56m ago
I don't know why everyone uses AI for important writing now. The other day management showed us a ChatGPT presentation apologising for being terrible at managing.
spyridonas · 1h ago
My HP screen (HP Aero 13, not a gaming laptop, with a integrated gpu only) does flicker, turning completely off and then on, and this issue doesn't appear when connecting to external monitor. The same happens under linux as well. This post had me curious about the ACPI now... maybe I can follow along !
giantpotato · 45m ago
article is great but it feels like its rewritten by an llm. " a crucial insight", "occurring like clockwork"
contrarian1234 · 42m ago
why is that a problem..?

Maybe the author is ESL or just not very good at writing...

If it's clearer and the information is still all correct - then isn't that great? More people can engage in clear communication with each other

orbital-decay · 20m ago
>and the information is still all correct

That's a pretty big if in technical writeups like this, all you do by rewriting those is obfuscate the actual inputs you had. Was is generated from scattered notes? Entirely vibe-written? How many details are actually verified to be correct by a human? Seeing how even the structure seems generated, it's clear that there was little input, and I'm not sure about any of the above.

I can deal with poor writing, and in case of ESL it's enough to tell the LLM to proofread/rephrase the piece (and check it yourself afterwards). But lazy generations just make you trust the article less.

taurath · 2h ago
I have one of these, a Zephyrus G15. That it had an AMD CPU and Nvidia GPU should have been a red flag that support would be really poor. Only a year out of warranty, it is a brick on a shelf because the thermals are so atrocious it pretty much burned itself out, and even with a thorough new application of thermal paste through a multi hour process there just isn't any way to get it to perform within spec. Supposedly, if you RMA it through ASUS they will charge you something like $700 and be unlikely to fix it. They have an insane dud rate, and even when it does work the hardware is barely hanging on. Several acquaintances have had similar problems.

It drastically reduced my perception of Asus as a brand - I wanted something I could game with, it promised the moon of portability and performance but they couldn't pull it off.

branko_d · 27m ago
Curious, my experience could not have been more different. I still use Asus Zephyrus G15 (GA503QR from 2021) as my main development machine, and also game occasionally on it. It's AMD Zen 3 CPU with GeForce 3070.

As I write this, the fans are either completely stopped or so slow that I cannot hear them. The fans can get a little "whooshy" under load, but nothing out of line with other Windows laptops, as far as I can tell.

I'm running under Windows profile (not one of the ASUS-specific ones in Armory Crate). I also limit the battery to 60%, since I'm mostly using it plugged-in, with external monitor and keyboard. A month ago, I upgraded RAM to 40 GB and added another 4 TB SSD (and cleaned the fans in the process, so it's even quieter). I think I'll keep this machine for a few more years...

That being said, I did experience occasional cursor stuttering, but mostly when the machine is under load (typically during Visual Studio build).

taurath · 10m ago
I believe I have the same one! For me, almost out of the box I needed to disable CPU boost due to the thermals and instability. That worked for a while, though I considered replacing it and didn’t because there was just no others available at the time due to the pandemic. Apparently my issue is common but not the majority - a lot of folks seem to just have gotten a bad batch. I’m curious though, have you not even had any issues with sleep mode on the laptop? It seems extremely common that it just doesn’t work/crashes.

I got a good 2.5 years out of it, but I was hoping to use it for at least 6 or 7.

xr8 · 38m ago
Great write up. As annoying failures are, always learn most from debugging sessions
nitinreddy88 · 2h ago
Out of curiosity, why not release BIOS mod with a fix? Atleast personal laptops (out of warranty) can benefit out of it until Asus fixes their sht.

People blame Windows being slow and etc but most of the times hardware manufactures don't even get into this level to make best out of thier hardware. This is the reason why Apple is so successful, they control hardware, software while in open world, software like Linux/Windows is written by someone while hardware is designed by someone else.

mrheosuper · 1h ago
Maybe the risk is too high ?, bricking UEFI means time for soldering/reflowing, because you won't be able to software-recover it(unless it has dual bios mechanism).
yusyusyus · 47m ago
not that simple to apply necessarily. lots of security junk on modern bios. keeps ya safe, ya know.
worthless-trash · 2h ago
I dont think it even needs a bios mod, i think you could get away with updating the acpi tables ( See https://docs.kernel.org/admin-guide/acpi/initrd_table_overri... )
immibis · 55m ago
Right, and Windows probably has something similar (maybe it requires loading a driver). This is BIOS-style code interpreted by the OS, so you can patch it at the OS level.
kaladin-jasnah · 2h ago
Perhaps there is firmware signing.
M95D · 2h ago
... and people are looking forward to signed UEFI and ACPI on ARM systems too. How do they expect an ACPI written in a chinese sweatshop will work if Asus quality is this low?
hypercube33 · 56m ago
I don't follow. My X13s is a Snapdragon, has full uefi, and works like a normal laptop, mostly. It can't stop from overheating and has no cooling but that's besides the point.
SchemaLoad · 1h ago
I assume all of these gaming laptops are largely developed by outsourced sweatshops today so I don't imagine much difference.
attila-lendvai · 49m ago
i'm craving for a world where hw manufacturers exist who fully embrace opensource development, and are rewarded for that...
taneq · 1h ago
I have a 2024 Zephyrus G14 and it has bursts of stuttering which seem to be directly linked to running off USB-C power. It doesn't do it on the original power brick, but on a 70W USB power brick, it slows down massively every now and then, to the point where the mouse cursor is only updating every few seconds and any playing audio starts underrunning buffers. Unplugging USB power immediately clears the issue up for a while. It's fine running off battery, and it's fine when I plug USB power back in, even straight away.

It does other stupid things with power management, too:

- There seems to be some "cooldown" logic that keeps it awake with the fan running for a while (sometimes minutes) after closing the lid. If I just unplug the laptop stick it straight in a backpack, it'll keep doing this (getting hotter and hotter, and burning half of the battery capacity) until it hits the critical high temp shutdown. It's great fun taking it out at the start of a plane flight and finding out it's on low battery and has bbq'd itself.

- Even if I do wait for the fan to turn off before stashing the laptop, when I open the lid and wake it up, it immediately goes into hibernate mode, and I have to wait for it to finish hibernating, turn it back on, and wait for it to boot up, which is really frustrating.

The solution to both of these (for me) is to reassign the power button to be 'hibernate' instead of 'sleep', and to explicitly hibernate it every time I'm packing it up. It's still stupid and annoying, and a damn shame because it's otherwise a really nice laptop. The OLED screen is beautiful and the build quality feels great. I just wish it wasn't crippled.

worthless-trash · 2h ago
I hacked the ACPI firmware on my system, linux is able to apply "my firmware" rather than use the operating system supplied firmware.

Does anyone know if windows can do the same ?

phs318u · 20m ago
This is what I was going to ask, but I assume that the ACPI.SYS driver (which wraps the ASUS ACPI BIOS implementation) is signed by Microsoft, which means "not unless you allow unsigned drivers", which I don't even know if that's possible in current Windows (my deep Windows-fu is about 20 years out of date).
jeroenhd · 1h ago
Microsoft documents replacing the ACPI table with their API: https://learn.microsoft.com/en-us/windows-hardware/drivers/b... (bottom of the page)

Unfortunately you need to disable signing for that, which will trigger anticheat in online games and makes Windows nag you about it.

Someone wrote a bootloader specifically to patch ACPI on boot in CSM mode if you're okay with reinstalling Windows on an older system that can't play certain games: https://github.com/MovAX0xDEAD/ACPI-Patcher