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In this web article "Working Around The Intel Core i7 5775C Broadwell Stability Issue On Linux", the author indicates that he and others have seen stability problems when running Linux on Broadwell-microarchitecture i7 processors. I am having similar issues with a i7-5700HQ. In both cases, a workaround related to SpeedStep or similar power/performance throttling was discovered.

Is it possible that Intel has released a microarchitecture which does not run Linux (reliably) without disabling frequency scaling -- or is it more likely that these issues are due to manufacturing defects in the particular hardware units under test?


Update: The problems were fixed for me with the BIOS/microcode update desribed here. As noted there, problems were discovered while running Windows as well. I don't have enough information about the update to know if this was Intel's fault or something specific to the manufacturer of my laptop.

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    The complexity of CPUs these days is mind-boggling. Consequently, a design screwup is overwhelmingly more likely than a conspiracy, if that's what you're asking. – lcd047 Jul 10 '15 at 18:38
  • @lcd047: A conspiracy isn't what I was thinking of -- but maybe just a lack of testing. That Linux would fail to run reliably on the architecture seems highly improbably, but that is what I am seeing. I really just want to know if my hardware is bad. But I can't make it crash running only Windows, so this makes a hardware defect seem unlikely as well. – nobar Jul 10 '15 at 18:45
  • It probably boils down to lack of testing, yes. On the other hand, if you have ever run coverage tests you probably know that getting 100% coverage is a pain in the rear even for a script with 1k lines. For a CPU we're literally talking about billions of transistors. Complete test coverage hasn't been possible even in theory since Intel 8080 in the mid 1970s. For this reason, I personally never buy anything based on technology more recent than 1-2 years. The difference in performance typically doesn't matter, but there are huge differences in price, and in bugs. – lcd047 Jul 10 '15 at 19:05
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Yes, I am using kubuntu. but it has some trick to make it stable.

First, please update you BIOS to latest version. I were use old version BIOS, windows 7/10 is stable, but Linux is not. It must disable speedstep to make it more stable until updated it.

Second, Kubuntu must update to mainline kernel . otherwise, it will get error message like "Working Around The Intel Core i7 5775C Broadwell Stability Issue On Linux" said.

I am using 4.2.0-RC7-unstable , it works good.

you can try it.

  • I'm not sure what you are saying about the kernel, but I did just find a BIOS update released the day after this answer was posted. I'm currently testing with that -- initial indications are good. – nobar Nov 1 '15 at 19:51
  • I am pretty confident that the BIOS update solved the problem for me. – nobar Nov 21 '15 at 18:53

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