6.2 KiB
These benchmarks are informal and only intended to give us a general sense of the benefit Dart Sass could provide relative to other implementations.
This was tested against:
- libsass da91d985 and sassc 66f0ef3 compiled with g++ (Debian 10.3.0-11) 10.3.0.
- Dart Sass bf318a8 on Dart 2.14.1 (stable) (Wed Sep 8 13:33:08 2021 +0200) on "linux_x64" and Node v16.10.0.
on Debian x64 with Intel Core i7-8650U CPU @ 1.90GHz.
Measurements
I ran five instances of each configuration and recorded the fastest time.
Small Plain CSS
Running on a file containing 4 instances of .foo {a: b}
:
- sassc: 0.002s
- Dart Sass from a script snapshot: 0.177s
- Dart Sass native executable: 0.009s
- Dart Sass on Node.js: 0.219s
Based on these numbers, Dart Sass from a native executable is approximately:
- 4.5x slower than libsass
- 24.3x faster than Dart Sass on Node
Large Plain CSS
Running on a file containing 2^17 instances of .foo {a: b}
:
- sassc: 1.607s
- Dart Sass from a script snapshot: 1.643s
- Dart Sass native executable: 1.473s
- Dart Sass on Node.js: 2.529s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.1x faster than libsass
- 1.7x faster than Dart Sass on Node
Preceding Sparse @extend
Running on a file containing .x {@extend .y}
, 2^17 instances of .foo {a: b}
, and then .y {a: b}
:
- sassc: 1.643s
- Dart Sass from a script snapshot: 1.723s
- Dart Sass native executable: 1.535s
- Dart Sass on Node.js: 2.574s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.1x faster than libsass
- 1.7x faster than Dart Sass on Node
Following Sparse @extend
Running on a file containing .y {a: b}
, 2^17 instances of .foo {a: b}
, and then .x {@extend .y}
:
- sassc: 1.642s
- Dart Sass from a script snapshot: 1.676s
- Dart Sass native executable: 1.517s
- Dart Sass on Node.js: 2.547s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.1x faster than libsass
- 1.7x faster than Dart Sass on Node
Preceding Dense @extend
Running on a file containing .bar {@extend .foo}
followed by 2^17 instances of .foo {a: b}
:
- sassc: 2.336s
- Dart Sass from a script snapshot: 2.453s
- Dart Sass native executable: 2.312s
- Dart Sass on Node.js: 5.874s
Based on these numbers, Dart Sass from a native executable is approximately:
- identical to libsass
- 2.5x faster than Dart Sass on Node
Following Dense @extend
Running on a file containing 2^17 instances of .foo {a: b}
followed by .bar {@extend .foo}
:
- sassc: 2.353s
- Dart Sass from a script snapshot: 2.357s
- Dart Sass native executable: 2.220s
- Dart Sass on Node.js: 5.587s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.1x faster than libsass
- 2.5x faster than Dart Sass on Node
Bootstrap
Running on a file containing 16 instances of importing the Bootstrap framework:
- sassc: 0.789s
- Dart Sass from a script snapshot: 1.517s
- Dart Sass native executable: 0.691s
- Dart Sass on Node.js: 2.799s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.1x faster than libsass
- 4.1x faster than Dart Sass on Node
a11ycolor
Running on a file containing test cases for a computation-intensive color-processing library:
- sassc: 0.205s
- Dart Sass from a script snapshot: 0.649s
- Dart Sass native executable: 0.245s
- Dart Sass on Node.js: 0.827s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.2x slower than libsass
- 3.4x faster than Dart Sass on Node
Duomo
Running on a file containing the output of the numerically-intensive Duomo framework (skipping LibSass due to module system use):
- Dart Sass from a script snapshot: 2.150s
- Dart Sass native executable: 1.406s
- Dart Sass on Node.js: 4.449s
Based on these numbers, Dart Sass from a native executable is approximately:
- 3.2x faster than Dart Sass on Node
Carbon
Running on a file containing the output of the import-intensive Carbon framework:
- sassc: 7.481s
- Dart Sass from a script snapshot: 5.891s
- Dart Sass native executable: 5.734s
- Dart Sass on Node.js: 15.725s
Based on these numbers, Dart Sass from a native executable is approximately:
- 1.3x faster than libsass
- 2.7x faster than Dart Sass on Node
Prior Measurements
- 1.22.6.
- 1.22.5.
- 1.22.4.
- 1.20.2.
- 1.13.4.
- 1.6.0.
- 1.0.0-alpha.8.
- Pre-alpha, 30 September 2016.
- Pre-alpha, 19 August 2016.
- Pre-alpha, 15 July 2016.
Conclusions
This is the first measurement with Dart Sass running as ahead-of-time-compiled native code, and the results are encouraging. It's well below the 100ms threshold for tiny files, and it's on par with SassC for most test cases. SassC still leads for tests with many extends, although only slightly, and for one of our real-world test cases (although Dart Sass leads in others). The two implementations can be fairly described as having about the same performance overall.
Dart Sass on Node is still substantially slower than on the Dart VM, and that relative slowdown becomes more pronounced as the raw Dart code becomes faster. Solutions for this such as the embedded protocol or WebAssembly support are becoming more and more important.