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You can use ThrottleStop[1] to disable PROCHOT on non-standard battery. I encountered similar issue with throttling on my Dell Precision laptop when I was charging it via 60 W USB-C charger instead of proprietary barrel-type 130 W plug. The system triggered a warning about low power charger and initiated aggressive cpu frequency scaling. By using ThrottleStop, I was able to use type-c 60W charger on lightweight tasks (such as web browsing, older games) just fine.

[1]: https://www.techpowerup.com/download/techpowerup-throttlesto...

I was the happy owner of ThinkPad X1 Extreme g1. It had that bug out of the box, new original battery. Once it thermal throttles, it never goes back to full GHz. It throttled pretty soon, cause big CPU small chassis. Yes, I had a script like that.

It is still somewhere on a shelf, so maybe its day will come again.

Nice to finally know what was happening to my x270 after so many years. Well good thing it doesn't happen when connected to power nowadays is my home server

Oh almost certainly. PROCHOT is programmable.

I wonder now if a similar problem is present in the A285 which is a cousin of the x270

Yeah, I wrote a similar script. Run it once I see the clock going to 400, but wait for eternity for the sudo prompt emerge before running it.

Possibly. Usually this is handled by the embedded controller, and not sure if that was reversed or not. You may be able to tristate the GPIO line that tells the CPU that a pin means PROCHOT, which would allow you to ignore the ECs attempts to do this.

Thinkpads do same thing when detecting 65W supply instead of 90W despite you only need 90W if running full tilt while charging.

Do you think it could also be due to an ACPI table?

Some people prefer to know exactly what their computer does, either to enable debugging in obscure cases or due to security concerns.

Thanks to Intel, who has invented the completely unnecessary System Management Mode, to compensate for the laziness of Microsoft, who could not be bothered to update MS-DOS and Windows with some features required in modern computers, now the BIOS has the ability to do whatever it wants on your computer, without this being detectable by the owner.

Hopefully the BIOS writers do not abuse this, and the many problems caused by BIOSes are due to unintentional bugs and not due to malice, but it would still better to be certain that your firmware does not do anything nefarious.

When debugging hardware problems, it is also much simpler when you are certain about what the computer really does, instead of not knowing whether the BIOS takes control when certain hardware events happen, overriding any policies that you may try to implement in your operating system.

Replacing the proprietary BIOS still does not provide complete control over what you own, as there are auxiliary CPUs with their own agenda, but it is still much closer to full control than when you do not know what the BIOS does.

The goal of that blog post is not to sell you something.

This can be confusing on HN, I know.

It replaces a proprietary component of your system with an open source one.

Reading https://libreboot.org/#why-use-libreboot might provide further enlightenment.

because the x280 and x270 are similar enough I didn't need to try very hard to get it to post or boot a live USB to further investigate (effectively acting as a decent template for me to work off of)

The console viewing itself was provided by `cbmem -1`, which I could run via a NixOS live USB with nixpkgs#coreboot-utils

You can sometimes find the serial lines if you are careful. Otherwise you can use the flashrom to store the output, and read it back out after each failure. It is much easier to just poke around and find the serial if you can, either from schematics (it seems the author has these) or by hand with a lot of patience or board scrying.

How's your experience with that? It's on the top of my dream laptop list but it's expensive and the second gen is more so....looks like they killed off the line right before it got to the sweet spot (ryzen ai max line) just like the surface laptop which makes me sad.

There were a lot of reports about those things having power or heat firmware problems?

sorry, I'll look into it

The PROCHOT discussion in this thread is a good example. Lenovo stops making batteries, third party ones trigger artificial throttling, and the only fix is poking registers with a boot script. With coreboot you can just... fix it properly.

More broadly: faster boot times (sub-second POST is common), no vendor bloat or hidden phone-home behavior in the firmware, and you can actually audit what runs before your OS loads. That last one matters more than people think. Your BIOS has full access to everything on the machine before any OS-level security even starts.

I am a trans woman, yes :o

(the user who posted my blog post is not me :p)

Seek and thou shalt find. Just don’t be too pushy on the romantic side of things.

Hi! As the author, no! I take a hard line stance against AI use myself. It's just not for me.

Does it matter?