turbostat man page

turbostat — Report processor frequency and idle statistics


turbostat [Options] command
turbostat [Options] [--interval seconds]


turbostat reports processor topology, frequency, idle power-state statistics, temperature and power on X86 processors. There are two ways to invoke turbostat. The first method is to supply a command, which is forked and statistics are printed upon its completion. The second method is to omit the command, and turbostat displays statistics every 5 seconds. The 5-second interval can be changed using the --interval option.

Some information is not available on older processors.


Options can be specified with a single or double '-', and only as much of the option name as necessary to disambiguate it from others is necessary. Note that options are case-sensitive.

--add attributes add column with counter having specified 'attributes'. The 'location' attribute is required, all others are optional.

location: {msrDDD | msr0xXXX}
	msrDDD is a decimal offset, eg. msr16
	msr0xXXX is a hex offset, eg. msr0x10

scope: {cpu | core | package}
	sample and print the counter for every cpu, core, or package.
	default: cpu

size: {u32 | u64 }
	MSRs are read as 64-bits, u32 truncates the displayed value to 32-bits.
	default: u64

format: {raw | delta | percent}
	'raw' shows the MSR contents in hex.
	'delta' shows the difference in values during the measurement interval.
	'percent' shows the delta as a percentage of the cycles elapsed.
	default: delta

--Dump displays the raw counter values.

--debug displays additional system configuration information. Invoking this parameter more than once may also enable internal turbostat debug information.

--interval seconds overrides the default 5.0 second measurement interval.

--out output_file turbostat output is written to the specified output_file. The file is truncated if it already exists, and it is created if it does not exist.

--help displays usage for the most common parameters.

--Joules displays energy in Joules, rather than dividing Joules by time to print power in Watts.

--Package limits output to the system summary plus the 1st thread in each Package.

--processor limits output to the system summary plus the 1st thread in each processor of each package. Ie. it skips hyper-threaded siblings.

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

--TCC temperature sets the Thermal Control Circuit temperature for systems which do not export that value. This is used for making sense of the Digital Thermal Sensor outputs, as they return degrees Celsius below the TCC activation temperature.

--version displays the version.

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

Default Field Descriptions

CPU Linux CPU (logical processor) number.  Yes, it is okay that on many systems the CPUs are not listed in numerical order -- for efficiency reasons, turbostat runs in topology order, so HT siblings appear together.
AVG_MHz number of cycles executed divided by time elapsed.
Busy% 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.

Debug Field Descriptions

Package processor package number.
Core processor core number.
Note that multiple CPUs per core indicate support for Intel(R) Hyper-Threading Technology (HT).
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.

Periodic Example

Without any parameters, turbostat displays statistics ever 5 seconds. Periodic output goes to stdout, by default, unless --out is used to specify an output file. The 5-second interval can be changed with th "-i sec" option. Or a command may be specified as in "Fork Example" below.

[root@hsw]# ./turbostat
     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
       -     488   12.51    3898    3498
       0       0    0.01    3885    3498
       4    3897   99.99    3898    3498
       1       0    0.00    3861    3498
       5       0    0.00    3882    3498
       2       1    0.02    3894    3498
       6       2    0.06    3898    3498
       3       0    0.00    3849    3498
       7       0    0.00    3877    3498

Debug Example

The "--debug" option prints additional system information before measurements:

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.

turbostat version 4.1 10-Feb, 2015 - Len Brown <lenb@kernel.org>
CPUID(0): GenuineIntel 13 CPUID levels; family:model:stepping 0x6:3c:3 (6:60:3)
RAPL: 3121 sec. Joule Counter Range, at 84 Watts
cpu0: MSR_NHM_PLATFORM_INFO: 0x80838f3012300
8 * 100 = 800 MHz max efficiency
35 * 100 = 3500 MHz TSC frequency
cpu0: MSR_IA32_POWER_CTL: 0x0004005d (C1E auto-promotion: DISabled)
cpu0: MSR_NHM_SNB_PKG_CST_CFG_CTL: 0x1e000400 (UNdemote-C3, UNdemote-C1, demote-C3, demote-C1, UNlocked: pkg-cstate-limit=0: pc0)
cpu0: MSR_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_CORE_PERF_LIMIT_REASONS, 0x31200000 (Active: ) (Logged: Auto-HWP, Amps, MultiCoreTurbo, Transitions, )
cpu0: MSR_GFX_PERF_LIMIT_REASONS, 0x00000000 (Active: ) (Logged: )
cpu0: MSR_RING_PERF_LIMIT_REASONS, 0x0d000000 (Active: ) (Logged: Amps, PkgPwrL1, PkgPwrL2, )
cpu0: MSR_RAPL_POWER_UNIT: 0x000a0e03 (0.125000 Watts, 0.000061 Joules, 0.000977 sec.)
cpu0: MSR_PKG_POWER_INFO: 0x000002a0 (84 W TDP, RAPL 0 - 0 W, 0.000000 sec.)
cpu0: MSR_PKG_POWER_LIMIT: 0x428348001a82a0 (UNlocked)
cpu0: PKG Limit #1: ENabled (84.000000 Watts, 8.000000 sec, clamp DISabled)
cpu0: PKG Limit #2: ENabled (105.000000 Watts, 0.002441* 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: 0x00641400 (100 C)
cpu0: MSR_IA32_PACKAGE_THERM_STATUS: 0x88340800 (48 C)
cpu0: MSR_IA32_THERM_STATUS: 0x88340000 (48 C +/- 1)
cpu1: MSR_IA32_THERM_STATUS: 0x88440000 (32 C +/- 1)
cpu2: MSR_IA32_THERM_STATUS: 0x88450000 (31 C +/- 1)
cpu3: MSR_IA32_THERM_STATUS: 0x88490000 (27 C +/- 1)
    Core     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp PkgWatt CorWatt GFXWatt
       -       -     493   12.64    3898    3498       0   12.64    0.00    0.00   74.72      47      47   21.62   13.74    0.00
       0       0       4    0.11    3894    3498       0   99.89    0.00    0.00    0.00      47      47   21.62   13.74    0.00
       0       4    3897   99.98    3898    3498       0    0.02
       1       1       7    0.17    3887    3498       0    0.04    0.00    0.00   99.79      32
       1       5       0    0.00    3885    3498       0    0.21
       2       2      29    0.76    3895    3498       0    0.10    0.01    0.01   99.13      32
       2       6       2    0.06    3896    3498       0    0.80
       3       3       1    0.02    3832    3498       0    0.03    0.00    0.00   99.95      28
       3       7       0    0.00    3879    3498       0    0.04

The max efficiency frequency, a.k.a. Low Frequency Mode, is the frequency available at the minimum package voltage. The TSC frequency is the base frequency of the processor -- this should match the brand string in /proc/cpuinfo. This base 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 not all information is available on all processors.

The --debug option adds additional columns to the measurement ouput, including CPU idle power-state residency processor temperature sensor readinds. See the field definitions above.

Fork Example

If turbostat is invoked with a command, it will fork that command and output the statistics gathered after the command exits. In this case, turbostat output goes to stderr, by default. Output can instead be saved to a file using the --out option. 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@hsw: turbostat cat /dev/zero > /dev/null
     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
       -     482   12.51    3854    3498
       0       0    0.01    1960    3498
       4       0    0.00    2128    3498
       1       0    0.00    3003    3498
       5    3854   99.98    3855    3498
       2       0    0.01    3504    3498
       6       3    0.08    3884    3498
       3       0    0.00    2553    3498
       7       0    0.00    2126    3498
10.783983 sec

Above the cycle soaker drives cpu5 up its 3.9 GHz turbo limit. The first row shows the average MHz and Busy% across all the processors in the system.

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. Alternatively, non-root users can be enabled to run turbostat this way:

# setcap cap_sys_rawio=ep ./turbostat

# chmod +r /dev/cpu/*/msr

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 MSRs in those kernels.

AVG_MHz = APERF_delta/measurement_interval. This is the actual number of elapsed cycles divided by the entire sample interval -- including idle time. Note that this calculation is resilient to systems lacking a non-stop TSC.

TSC_MHz = TSC_delta/measurement_interval. On a system with an invariant TSC, this value will be constant and will closely match the base frequency value shown in the brand string in /proc/cpuinfo. On a system where the TSC stops in idle, TSC_MHz will drop below the processor's base frequency.

Busy% = MPERF_delta/TSC_delta

Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/measurement_interval

Note that these calculations depend on TSC_delta, so they are not reliable during intervals when TSC_MHz is not running at the base frequency.

Turbostat data collection is not atomic. Extremely short measurement intervals (much less than 1 second), or system activity that prevents turbostat from being able to run on all CPUS to quickly collect data, will result in inconsistent results.

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.


Volume 3B: System Programming Guide" http://www.intel.com/products/processor…



See Also

msr(4), vmstat(8)


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

Referenced By