Stephen John Smoogen <smooge at gmail.com> writes: > On 3 October 2017 at 13:01, hw <hw at adminart.net> wrote: >> Stephen John Smoogen <smooge at gmail.com> writes: >> >>> On 1 October 2017 at 11:34, hw <hw at adminart.net> wrote: >>>> Hi, >>>> >>>> is there a way in Centos to find out if the Intel turbo mode will be >>>> used? >>>> >>>> Using the 'stress' utility and checking the frequency with cpupower >>>> tells me that a CPU is running at it´s maximum frequency as reported by >>>> cpupower --- and this frequency is less than the frequency it would run >>>> at if it used the turbo mode. All the other CPUs are at their minimum >>>> frequency. I have verified that turbo mode is enabled in the BIOS. >>>> >>>> Is cpupower unable to report frequencies used in turbo mode despite it >>>> always says it gets its information from the hardware? >>>> >>> >>> It would seem that there are multiple ways to get the information you >>> are looking for. I expect you have seen this already >>> >>> https://haypo.github.io/intel-cpus.html >>> >>> but I figured I would pass it on for others. They found that cpupower >>> is less reliable in how it reports the data because of the values it >>> gets them from. >> >> Thanks, I didn´t see that one yet. At least I noticed that cpupower >> says that turbo mode is available, and turbostat seems to indicate that >> CPUs sometimes run at higher frequencies like they would when in turbo >> mode. >> >> It´s strange that there is no tool to definitely figure this out, >> especially since RH seems to have done a lot of research into improving >> performance. >> > > My limited understanding is that it isn't very reliable to show it and > the Windows ones distort reality a lot (aka say you are in it when you > aren't actually in it) because they do a moving average to show what > is going on so it doesn't look as jagged as it really is. I guess the same could be said for turbostat because it show some computed frequency. > It is also not all that useful for general software needs. The CPU is > going to be waiting a lot longer now for memory and io to catch up for > most transactions. Does it hurt anything when it waits faster? It might have the advantage that it doesn´t wait longer than it otherwise would and processes things somewhat faster when it finally does. For how long it takes until processing is finished, it doesn´t matter if the CPU waits longer when it still takes the same amount of time, and chances are it might not take as long. Or am I mistaken? Anyway, it seems to me as if there´s actually no way to figure out if the CPU is at turbo frequencies because it decides that for itself. But then, I have an E3-1230 V2 here, and even cpupower reports its turbo frequencies. -- "Didn't work" is an error.