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If you like testing or just checking up on your computer’s hardware specifications, you might be surprised to see different operating systems provide conflicting information about your hardware. Why is that? Today’s SuperUser Q&A post helps clear up the confusion for a concerned reader.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

Screenshot courtesy of Karan Raj Baruah (SuperUser).

The Question

SuperUser reader Daniel Sebestyen wants to know why different operating systems are providing conflicting hardware specification information:

I have a 3.6 GHz AMD FM2 A8-Series A8 5600K CPU (factory specs) and there is at least a 0.2 GHz difference between hardware reports on Windows and Linux.

The hardware was checked on the following operating systems:

  • Windows 7 Ultimate x64 & x86 (both tests showed 3.4 GHz)
  • Windows 8.1 Pro x64 & x86 (both tests showed 3.5 GHz)
  • Ubuntu 14.10 & 14.10.1 x86 & x64 (tests displayed the correct amount, 3.6 GHz )
  • Linux Mint 17 (x86 & x64, tests on Mate showed 3.55 GHz; x86 & x64 tests on Cinnamon displayed the correct amount, 3.6 GHz )

I know the CPU and my ASROCK motherboard have the ability to over-clock, but it is not enabled, so I do not think that will affect hardware tests.

Does anyone know if it is a sign of broken/damaged hardware or is it just differences between operating systems?

Why is Daniel getting different results for the same hardware?

The Answer

SuperUser contributors Karan Raj Baruah and user201235 have the answer for us. First up, Karan Raj Baruah:

I would recommend something like Speccy to get accurate specification information for your PC.

The Task Manager in Windows 8/8.1 always shows the present clock for your CPU. Sometimes when power saving modes are enabled (especially in laptops), the processor under-clocks on the go to save power and you will see a smaller number in the Task Manager.

Followed by the answer from user201235:

Even without over-clocking or under-clocking, modern CPUs change their speed. They can enter turbo mode or power saving mode (and dip way way down). The difference in the exact background processes running is what accounts for the difference in reported speed.

In fact, many CPU monitoring programs let you observe the changes in speed in real time as you run and/or close programs.


Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.