CPU Frequency Calculator
Calculate effective CPU clock frequency accounting for turbo boost and throttling.
About CPU Frequency Calculator
Modern CPUs rarely run all cores at their advertised maximum turbo frequency simultaneously — thermal and power (TDP) limits mean all-core turbo is typically lower than single-core turbo, so only a fraction of cores can sustain the boosted clock under full load. This calculator models aggregate throughput as a GHz-equivalent sum: some cores running at the turbo frequency (base × boost factor) and the rest at base clock, which better approximates real sustained multi-threaded performance than naively multiplying base frequency by boost factor by total core count.
Formula
Aggregate throughput
aggregate = turbo_cores × (base_freq × boost_factor) + base_cores × base_freq
- n_t
- cores sustaining turbo
- f_b
- base frequency
- k
- turbo boost factor
- n_b
- cores at base clock
Worked example
With the default values below, CPU Frequency Calculator returns Aggregate Compute Throughput (GHz-equivalent) of 25.20. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Base Frequency (GHz)minimum 0.1
- 2.4
- Turbo Boost Factor (× base)minimum 1
- 1.5
- Active Coresminimum 1
- 8
- Fraction of Cores That Can Sustain Turboaccepts 0–100
- 60
Results
- Aggregate Compute Throughput (GHz-equivalent)
- 25.20
- Effective Avg GHz per Core
- 3.150
- Single-Core Turbo Frequency (GHz)
- 3.600
- Theoretical Max (all cores at turbo)
- 28.80
- Cores Sustaining Turbo
- 5
- Cores at Base Clock
- 3
Step by step
- 1Values used
- 2Aggregate throughput
- 3Aggregate Compute Throughput (GHz-equivalent)= 25.20
- 4Effective Avg GHz per Core= 3.150
- 5Single-Core Turbo Frequency (GHz)= 3.600
- 6Theoretical Max (all cores at turbo)= 28.80
- 7Cores Sustaining Turbo= 5
- 8Cores at Base Clock= 3
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges into account.
- Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Why doesn't my CPU run all cores at the maximum turbo frequency listed on the box?
The advertised max turbo is typically a single-core (or few-core) boost limited by the chip's power and thermal budget. Loading every core simultaneously draws far more power, so the CPU's power management (governed by Intel Turbo Boost or AMD Precision Boost) lowers the sustained all-core frequency to stay within TDP.
How can I check my CPU's actual current frequency on Linux?
`cat /proc/cpuinfo | grep MHz` shows per-core current frequency, and `watch -n1 'grep MHz /proc/cpuinfo'` lets you watch it change live under load. `cpupower frequency-info` gives a more detailed governor and scaling driver view.
Does the cpufreq governor affect this calculation?
Indirectly — the 'performance' governor keeps cores near maximum frequency more aggressively, while 'powersave' or 'ondemand'/'schedutil' scale down during idle periods, meaning actual sustained frequency under intermittent load can be lower than either base or turbo estimates used here.