turbostat - Report processor frequency and idle statistics turbostat [ Options ] command

turbostat [ Options ] [ "-i interval_sec" ]

turbostat reports processor topology, frequency, idle power-state statistics, temperature and power on modern X86 processors. Either command is forked and statistics are printed upon its completion, or statistics are printed periodically. turbostat must be run on root, and minimally requires that the processor supports an "invariant" TSC, plus the APERF and MPERF MSRs. Additional information is reported depending on hardware counter support. The -p option limits output to the 1st thread in 1st core of each package.

The -P option limits output to the 1st thread in each Package.

The -S option limits output to a 1-line System Summary for each interval.

The -v option increases verbosity.

The -c MSR# option includes the delta of the specified 32-bit MSR counter.

The -C MSR# option includes the delta of the specified 64-bit MSR counter.

The -m MSR# option includes the the specified 32-bit MSR value.

The -M MSR# option includes the the specified 64-bit MSR value.

The -i interval_sec option prints statistics every \fiinterval_sec seconds. The default is 5 seconds.

The command parameter forks command and upon its exit, displays the statistics gathered since it was forked.

Package processor package number.
Core processor core number.
CPU Linux CPU (logical processor) number.
Note that multiple CPUs per core indicate support for Intel(R) Hyper-Threading Technology.
AVG_MHz number of cycles executed divided by time elapsed.
%Buzy percent of the interval that the CPU retired instructions, aka. % of time in "C0" state.
Bzy_MHz average clock rate while the CPU was busy (in "c0" state).
TSC_MHz average MHz that the TSC ran during the entire interval.
CPU%c1, CPU%c3, CPU%c6, CPU%c7 show the percentage residency in hardware core idle states.
CoreTmp Degrees Celsius reported by the per-core Digital Thermal Sensor.
PkgTtmp Degrees Celsius reported by the per-package Package Thermal Monitor.
Pkg%pc2, Pkg%pc3, Pkg%pc6, Pkg%pc7 percentage residency in hardware package idle states.
PkgWatt Watts consumed by the whole package.
CorWatt Watts consumed by the core part of the package.
GFXWatt Watts consumed by the Graphics part of the package -- available only on client processors.
RAMWatt Watts consumed by the DRAM DIMMS -- available only on server processors.
PKG_% percent of the interval that RAPL throttling was active on the Package.
RAM_% percent of the interval that RAPL throttling was active on DRAM.

Without any parameters, turbostat prints out counters ever 5 seconds. (override interval with "-i sec" option, or specify a command for turbostat to fork). The first row of statistics is a summary for the entire system. For residency % columns, the summary is a weighted average. For Temperature columns, the summary is the column maximum. For Watts columns, the summary is a system total. Subsequent rows show per-CPU statistics.

[root@ivy]# ./turbostat
 Core CPU Avg_MHz %Busy Bzy_MHz TSC_MHz SMI CPU%c1 CPU%c3 CPU%c6 CPU%c7 CoreTmp PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 PkgWatt CorWatt GFXWatt 
 - - 6 0.36 1596 3492 0 0.59 0.01 99.04 0.00 23 24 23.82 0.01 72.47 0.00 6.40 1.01 0.00
 0 0 9 0.58 1596 3492 0 0.28 0.01 99.13 0.00 23 24 23.82 0.01 72.47 0.00 6.40 1.01 0.00
 0 4 1 0.07 1596 3492 0 0.79
 1 1 10 0.65 1596 3492 0 0.59 0.00 98.76 0.00 23
 1 5 5 0.28 1596 3492 0 0.95
 2 2 10 0.66 1596 3492 0 0.41 0.01 98.92 0.00 23
 2 6 2 0.10 1597 3492 0 0.97
 3 3 3 0.20 1596 3492 0 0.44 0.00 99.37 0.00 23
 3 7 5 0.31 1596 3492 0 0.33

The "-v" option adds verbosity to the output:

[root@ivy]# turbostat -v
turbostat v3.0 November 23, 2012 - Len Brown <lenb@kernel.org>
CPUID(0): GenuineIntel 13 CPUID levels; family:model:stepping 0x6:3a:9 (6:58:9)
CPUID(6): APERF, DTS, PTM, EPB
RAPL: 851 sec. Joule Counter Range
cpu0: MSR_NHM_PLATFORM_INFO: 0x81010f0012300
16 * 100 = 1600 MHz max efficiency
35 * 100 = 3500 MHz TSC frequency
cpu0: MSR_NHM_SNB_PKG_CST_CFG_CTL: 0x1e008402 (UNdemote-C3, UNdemote-C1, demote-C3, demote-C1, locked: pkg-cstate-limit=2: pc6-noret)
cpu0: MSR_NHM_TURBO_RATIO_LIMIT: 0x25262727
37 * 100 = 3700 MHz max turbo 4 active cores
38 * 100 = 3800 MHz max turbo 3 active cores
39 * 100 = 3900 MHz max turbo 2 active cores
39 * 100 = 3900 MHz max turbo 1 active cores
cpu0: MSR_IA32_ENERGY_PERF_BIAS: 0x00000006 (balanced)
cpu0: MSR_RAPL_POWER_UNIT: 0x000a1003 (0.125000 Watts, 0.000015 Joules, 0.000977 sec.)
cpu0: MSR_PKG_POWER_INFO: 0x01e00268 (77 W TDP, RAPL 60 - 0 W, 0.000000 sec.)
cpu0: MSR_PKG_POWER_LIMIT: 0x830000148268 (UNlocked)
cpu0: PKG Limit #1: ENabled (77.000000 Watts, 1.000000 sec, clamp DISabled)
cpu0: PKG Limit #2: ENabled (96.000000 Watts, 0.000977* sec, clamp DISabled)
cpu0: MSR_PP0_POLICY: 0
cpu0: MSR_PP0_POWER_LIMIT: 0x00000000 (UNlocked)
cpu0: Cores Limit: DISabled (0.000000 Watts, 0.000977 sec, clamp DISabled)
cpu0: MSR_PP1_POLICY: 0
cpu0: MSR_PP1_POWER_LIMIT: 0x00000000 (UNlocked)
cpu0: GFX Limit: DISabled (0.000000 Watts, 0.000977 sec, clamp DISabled)
cpu0: MSR_IA32_TEMPERATURE_TARGET: 0x00691400 (105 C)
cpu0: MSR_IA32_PACKAGE_THERM_STATUS: 0x884e0000 (27 C)
cpu0: MSR_IA32_THERM_STATUS: 0x88560000 (19 C +/- 1)
cpu1: MSR_IA32_THERM_STATUS: 0x88560000 (19 C +/- 1)
cpu2: MSR_IA32_THERM_STATUS: 0x88540000 (21 C +/- 1)
cpu3: MSR_IA32_THERM_STATUS: 0x884e0000 (27 C +/- 1)
 ...

The max efficiency frequency, a.k.a. Low Frequency Mode, is the frequency available at the minimum package voltage. The TSC frequency is the nominal maximum frequency of the processor if turbo-mode were not available. This frequency should be sustainable on all CPUs indefinitely, given nominal power and cooling. The remaining rows show what maximum turbo frequency is possible depending on the number of idle cores. Note that this information is not available on all processors. If turbostat is invoked with a command, it will fork that command and output the statistics gathered when the command exits. eg. Here a cycle soaker is run on 1 CPU (see %c0) for a few seconds until ^C while the other CPUs are mostly idle:

root@ivy: turbostat cat /dev/zero > /dev/null
^C
 Core CPU Avg_MHz %Busy Bzy_MHz TSC_MHz SMI CPU%c1 CPU%c3 CPU%c6 CPU%c7 CoreTmp PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 PkgWatt CorWatt GFXWatt 
 - - 496 12.75 3886 3492 0 13.16 0.04 74.04 0.00 36 36 0.00 0.00 0.00 0.00 23.15 17.65 0.00
 0 0 22 0.57 3830 3492 0 0.83 0.02 98.59 0.00 27 36 0.00 0.00 0.00 0.00 23.15 17.65 0.00
 0 4 9 0.24 3829 3492 0 1.15
 1 1 4 0.09 3783 3492 0 99.91 0.00 0.00 0.00 36
 1 5 3880 99.82 3888 3492 0 0.18
 2 2 17 0.44 3813 3492 0 0.77 0.04 98.75 0.00 28
 2 6 12 0.32 3823 3492 0 0.89
 3 3 16 0.43 3844 3492 0 0.63 0.11 98.84 0.00 30
 3 7 4 0.11 3827 3492 0 0.94
30.372243 sec

Above the cycle soaker drives cpu5 up its 3.8 GHz turbo limit while the other processors are generally in various states of idle. Note that cpu1 and cpu5 are HT siblings within core1. As cpu5 is very busy, it prevents its sibling, cpu1, from entering a c-state deeper than c1. Note that the Avg_MHz column reflects the total number of cycles executed divided by the measurement interval. If the %Busy column is 100%, then the processor was running at that speed the entire interval. The Avg_MHz multiplied by the %Busy results in the Bzy_MHz -- which is the average frequency while the processor was executing -- not including any non-busy idle time. "turbostat " must be run as root. "turbostat " reads hardware counters, but doesn't write them. So it will not interfere with the OS or other programs, including multiple invocations of itself. turbostat may work poorly on Linux-2.6.20 through 2.6.29, as acpi-cpufreq periodically cleared the APERF and MPERF in those kernels. If the TSC column does not make sense, then the other numbers will also make no sense. Turbostat is lightweight, and its data collection is not atomic. These issues are usually caused by an extremely short measurement interval (much less than 1 second), or system activity that prevents turbostat from being able to run on all CPUS to quickly collect data. The APERF, MPERF MSRs are defined to count non-halted cycles. Although it is not guaranteed by the architecture, turbostat assumes that they count at TSC rate, which is true on all processors tested to date. "Intel® Turbo Boost Technology in Intel® Core™ Microarchitecture (Nehalem) Based Processors" http://download.intel.com/design/processor/applnots/320354.pdf "Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3B: System Programming Guide" http://www.intel.com/products/processor/manuals/

/dev/cpu/*/msr

msr(4), vmstat(8)

Written by Len Brown <len.brown@intel.com>