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. -- "Didn't work" is an error.
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. 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. -- Stephen J Smoogen.
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.