3 ms·

so riddle me this, under what circumstances does the cpu fan not spin? i'm having a hard time imagining a computer booting, without a cpu fan. OS: I'm starting

so riddle me this, under what circumstances does the cpu fan not spin? i'm having a hard time imagining a computer booting, without a cpu fan. OS: I'm starting up - so do all these things! as fast as possible!

ori_b 11y ago
I think you have it backwards: The CPU fan spins. Until the OS (or the AML bytecode that the OS interprets as a part of ACPI) tells it "the CPU is cool right now, you can slow down and save power".
- throwawayaway 11y ago
  > On a Thinkpad T500, you do need Lenovos special power management tools. Otherwise, the cpu fan will never spin up and your processor will overheat. I am replying to this guy. Never spin up? Overheat? He's completely wrong. I know full well how it works, I don't have it backwards.
  - tsomctl 11y ago
    I'm pretty sure you're trolling, but I'll feed you. I wasn't fully clear. Really what I meant is that the fan always spins at a slow speed. When the processor heats up, the fan doesn't speed up, and eventually the cpu shuts down to protect itself. And I've spent 12 hours a day in front of this computer for the past 5 years. I know how it works.
nitrogen 11y ago
It can be a combination of factors: - The CPU fan might be controlled via ACPI. - The operating system is supposed to run ACPI code provided by the BIOS. - A BIOS can specify different sets of ACPI code for different operating systems, so Linux might get different code from Windows. - The ACPI code provided by the BIOS for Linux might be broken, or lacking fan control. - The hardware vendor may have decided not to provide APCI controls for anything, relying instead on proprietary interfaces. Section 1.9 of https://www.kernel.org/doc/ols/2005/ols2005v1-pages-59-76.pdf https://www.kernel.org/doc/ols/2005/ols2005v1-pages-59-76.pd... looks like it might be related.

3 ms·

so riddle me this, under what circumstances does the cpu fan not spin? i'm having a hard time imagining a computer booting, without a cpu fan. OS: I'm starting

by throwawayaway 11y ago

ori_b 11y ago
I think you have it backwards: The CPU fan spins. Until the OS (or the AML bytecode that the OS interprets as a part of ACPI) tells it "the CPU is cool right now, you can slow down and save power".
- throwawayaway 11y ago
  > On a Thinkpad T500, you do need Lenovos special power management tools. Otherwise, the cpu fan will never spin up and your processor will overheat. I am replying to this guy. Never spin up? Overheat? He's completely wrong. I know full well how it works, I don't have it backwards.
  - tsomctl 11y ago
    I'm pretty sure you're trolling, but I'll feed you. I wasn't fully clear. Really what I meant is that the fan always spins at a slow speed. When the processor heats up, the fan doesn't speed up, and eventually the cpu shuts down to protect itself. And I've spent 12 hours a day in front of this computer for the past 5 years. I know how it works.
nitrogen 11y ago
It can be a combination of factors: - The CPU fan might be controlled via ACPI. - The operating system is supposed to run ACPI code provided by the BIOS. - A BIOS can specify different sets of ACPI code for different operating systems, so Linux might get different code from Windows. - The ACPI code provided by the BIOS for Linux might be broken, or lacking fan control. - The hardware vendor may have decided not to provide APCI controls for anything, relying instead on proprietary interfaces. Section 1.9 of https://www.kernel.org/doc/ols/2005/ols2005v1-pages-59-76.pdf https://www.kernel.org/doc/ols/2005/ols2005v1-pages-59-76.pd... looks like it might be related.