Spurious thermal shutdowns on Dell Studio 1557

Bartosz Fabianowski freebsd at chillt.de
Sat Apr 3 23:03:28 UTC 2010


> you would like to be able use this machine to full extent and keep
> temperature below the critical shutdown level.

Ideally, yes. I do not need much CPU power throughout most of the day. 
But when a larger update comes along and it is time to rebuild say 
OpenOffice.org, I would really like to exercise the CPU to its fullest. 
This is why I bought it after all.

> [snip]
>
> The latter will ensure that your fan will run at highest setting for
>  at least 2 minutes, even if temperature drops below 71C.

Very interesting tips. I will experiment with different settings and see 
whether I can make the machine run cooler. A very low-tech solution I am 
planning to apply later tonight is to hoover all air vents. Even though 
the machine is very new, there might be some dust stuck somewhere.

> If this is not sufficient, you can also modify your ASL

I did think of that. Unfortunately, the ASL produced by acpidump -d does 
not recompile, producing over 200 errors. They all have to do with 
references to a non-existent table. I will probably be able to solve 
them all by fixing a single typo somewhere. Again something I will look 
into for sure.

> If you go this route, I would strongly recommend reading thermal
> chapter of the ACPI spec -- it is short, well written and contains
> well-commented example.

I have the ACPI spec here - will have a look at that chapter, thanks.

> please, understand that this route is more then moderately dangerous
>  and could cause harm to your system.

Yes, I am aware of that. Then again, I have a system that out-of-the-box
is running way too hot. If I just ignore the issue, the system may harm 
itself. Trying to do something about it IMHO is the better way.

> If all of the above fails, I would dare say that your system was not
> designed to withstand the use you have intended for it and you will
> need to resort to hardware modifications (more powerful fan, case
> fan, water cooling, etc.).

Case fan, water cooling - now that will make for one interesting laptop :).

Having read various forums, I am beginning to think the system was 
really not designed to handle its CPU's thermal requirements. Apparently 
Dell has a questionable track record when it comes to thermal design. 
Still, I paid for a piece of hardware and now I expect to use it.

Granted, this machine might have been built to run under Windows. But 
the fan control settings and thermal thresholds would all be the same 
there. So even with the supplied OS, the machine would be running too 
hot and shutting down. This is clearly not acceptable. I think I will 
contact Dell support and see what they can do for me. Of course, 
first-level support is just there to read off scripts... I might have a 
difficult time getting through to someone who actually understands the 
issue.

- Bartosz


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