Use of both `--sort command` and `--reference` options leads to confusing relative speed table
Author: raviqqeCreated Mar 30, 2025Updated May 17, 2026
When --sort command and --reference options are used together, Hyperfine drops faster than and slower than annotations from relative speed tables where everything looks slower than references.
Examples
Only --reference
You see faster than and slower than adjectives in the summary table.
> hyperfine --reference 'sleep 2' 'sleep 1' 'sleep 3'
Benchmark 1: sleep 2
Time (mean ± σ): 2.014 s ± 0.003 s [User: 0.004 s, System: 0.004 s]
Range (min … max): 2.006 s … 2.018 s 10 runs
Benchmark 2: sleep 1
Time (mean ± σ): 1.020 s ± 0.010 s [User: 0.004 s, System: 0.004 s]
Range (min … max): 1.010 s … 1.045 s 10 runs
Benchmark 3: sleep 3
Time (mean ± σ): 3.018 s ± 0.004 s [User: 0.005 s, System: 0.005 s]
Range (min … max): 3.012 s … 3.022 s 10 runs
Summary
sleep 2 ran
1.97 ± 0.02 times slower than sleep 1
1.50 ± 0.00 times faster than sleep 3--reference and --sort command
You do not see faster than and slower than adjectives in the relative speed comparison table.
> hyperfine --sort command --reference 'sleep 2' 'sleep 1' 'sleep 3'
Benchmark 1: sleep 2
Time (mean ± σ): 2.014 s ± 0.003 s [User: 0.003 s, System: 0.003 s]
Range (min … max): 2.007 s … 2.017 s 10 runs
Benchmark 2: sleep 1
Time (mean ± σ): 1.015 s ± 0.002 s [User: 0.004 s, System: 0.003 s]
Range (min … max): 1.011 s … 1.017 s 10 runs
Benchmark 3: sleep 3
Time (mean ± σ): 3.016 s ± 0.001 s [User: 0.004 s, System: 0.004 s]
Range (min … max): 3.013 s … 3.017 s 10 runs
Relative speed comparison
1.00 sleep 2
1.98 ± 0.01 sleep 1
1.50 ± 0.00 sleep 3Solution
I think there are two options.
- Add
faster thanandslower thanannotations when both--sort commandand--referenceoptions are specified. - Use relative speeds below 1 for candidates faster than references.
Source: sharkdp/hyperfine