Luca's meaningless thoughts  

Fuck! I bought this extremely nice ultrabook, the Toshiba Satellite Z830-10J, about an year ago, and I've been experiencing some problems with CPU frequency scaling.

At one point I looked and looked for kernel bugs without much success. I went through several kernel updates in the hope of this being fixed, but never happened.

It seemed that the problem wasn't so bad after all, because I only got the CPU frequency locked down to the minimum when using the ondemand scaling governor, but the conservative was working apparently OK.

Just a little more latency I thought, is not that bad.

Recently I received an update on a related bug and I thought about giving it another shot. This mentioned something about booting with processor.ignore_ppc=1 to ignore some BIOS warning about temperature to overcome some faulty BIOS, so I thought on trying that.

But before doing, if this were a real BIOS problem, I thought about looking for some BIOS update. And there was one. The European Toshiba website offered only a Windows program to do the update though, but fortunately I found in a forum a suggestion about using the non-European BIOS upgrade instead, which was provided also as an ISO image. The problem is I don't have a CD-ROM, but that shouldn't stop me, I still have USB sticks and hard-drives, how hard could it be? I failed with UNetbootin but quickly found a nice article explaining how to boot an ISO image directly with grub.

BIOS upgraded, problem not fixed. So I was a about to try the kernel parameter when I remembered I saw some other article when googling desperately for answers suggesting changing some BIOS options to fix a similar problem.

So I though about messing with the BIOS first instead. The first option I saw that looked a little suspicious was in:

PowerManagement
   -> BIOS Power Management
      -> Battery Save Mode (using custom settings)
         -> Processor Speed
            <Low>

That is supposed to be only for non-ACPI capable OS, so I thought it shouldn't be a problem, but I tried with <High> instead.

WOW!!!

I start noticing the notebook booting much faster, but I thought maybe it was all in my mind...

But no, then my session opened way faster too, and everything was extremely faster. I think maybe about twice as fast. Everything feels a lot more responsive too. I can't believe I spend almost an year with this performance penalty. FUCKING FAULTY BIOS. I didn't make any battery life comparisons yet, but my guess is everything will go well, because it should still consume very little power when idle.

Anyway, lesson learned:

Less blaming to the kernel, more blaming to the hardware manufacturers.

But I still want to clarify that I love this notebook. I found it a perfect combination between features, weight and battery life, and now that it runs twice as fast (at least in my brain), is even better.

Hope this is useful for someone.