zstd Output Buffer Compression Benchmark in PHP

Just heard the news that Chrome is rolling now with support for "Content-Encoding: zstd". Whoa! Finally.

Now let's put some pressure on the not-so-more innovative folk at Mozilla/Firefox.

Anyhow, here are my

Results

  /* zstd: */   ob_start(function(&$data) { return zstd_compress($data, $level); });
  /* gzip: */   ob_start(function(&$data) { return gzencode($data); });
  /* obgz: */   ob_start('ob_gzhandler');
  /* none: */   ob_start(); # No compression with default config, i.e. zlib.output_compression = Off 

  # none......:  4,039,229 Bytes;  100 requests in   3.16 secs  (avg=0.0316 s per req)
  # gzip......:  1,290,963 Bytes;  100 requests in  17.65 secs  (avg=0.1765 s per req)
  # obgz......:  1,290,963 Bytes;  100 requests in  17.27 secs  (avg=0.1727 s per req)
  # zstd1.....:  1,392,549 Bytes;  100 requests in   4.01 secs  (avg=0.0401 s per req)
  # zstd2.....:  1,310,025 Bytes;  100 requests in   4.32 secs  (avg=0.0432 s per req)
  # zstd3.....:  1,240,800 Bytes;  100 requests in   4.45 secs  (avg=0.0445 s per req)
  # zstd4.....:  1,222,309 Bytes;  100 requests in   4.76 secs  (avg=0.0476 s per req)
  # zstd5.....:  1,195,749 Bytes;  100 requests in   5.84 secs  (avg=0.0584 s per req)
  # zstd6.....:  1,157,140 Bytes;  100 requests in   6.94 secs  (avg=0.0694 s per req)
  # zstd7.....:  1,133,898 Bytes;  100 requests in   8.18 secs  (avg=0.0818 s per req)
  # zstd8.....:  1,120,307 Bytes;  100 requests in   9.71 secs  (avg=0.0971 s per req)
  # zstd9.....:  1,115,600 Bytes;  100 requests in   9.80 secs  (avg=0.0980 s per req)
  # zstd10....:  1,095,873 Bytes;  100 requests in  12.33 secs  (avg=0.1233 s per req)
  # zstd11....:  1,082,522 Bytes;  100 requests in  18.20 secs  (avg=0.1820 s per req)
  # zstd12....:  1,081,317 Bytes;  100 requests in  21.91 secs  (avg=0.2191 s per req)
  # zstd13....:  1,059,720 Bytes;  100 requests in  52.40 secs  (avg=0.5240 s per req)
  # zstd14....:  1,044,099 Bytes;  100 requests in  67.91 secs  (avg=0.6791 s per req)
  # zstd15....:  1,036,078 Bytes;  100 requests in  87.37 secs  (avg=0.8737 s per req)
  # zstd16....:    983,006 Bytes;  100 requests in 103.78 secs  (avg=1.0378 s per req)
  # zstd17....:    980,923 Bytes;  100 requests in 115.09 secs  (avg=1.1509 s per req)
  # zstd18....:    972,316 Bytes;  100 requests in 141.62 secs  (avg=1.4162 s per req)
  # zstd19....:    971,972 Bytes;  100 requests in 145.05 secs  (avg=1.4505 s per req)
  # zstd20....:    971,972 Bytes;  100 requests in 146.45 secs  (avg=1.4645 s per req)
  # zstd21....:    971,972 Bytes;  100 requests in 148.13 secs  (avg=1.4813 s per req)
  # zstd22....:    971,962 Bytes;  100 requests in 152.34 secs  (avg=1.5234 s per req)

Source document is a 4 MB long HTML file, Project Gutenberg's rendition of War and Peace, served thru PHP script war_and_peace.php which applies output buffer compression as requested.

Interpretation

• gzip handling via the built-in ob_gzhandler equals manually calling gzencode.
• gzip is horribly slow and should be dumped from production servers. Feed bad clients raw uncompressed stuff, if you don't need to pay for traffic.
• ~.01 sec overhead (over uncompressed) for amazing compression at zstd level 3 is super neglectable.
• ...compared to the ~.13 sec overhead of using on-the-fly gzip!
• zstd levels 3 (default) .. 10 outperform gzip both time-wise and compression-wise
• zstd levels 1 and 2 don't really matter

Requirements

• A web server
• PHP (written with PHP 8.3, older major versions may work)
• The great zstd extension by @kjdev

How to run this yourself

Example call:

php8.3 benchmark.php "https://localhost/zstdtest/war_and_peace.php?compression="

The compression= is left blank, as it's fed by benchmark.php during runtime.

The target, war_and_peace.php, contain the following snippets:

$comp = $_GET['compression'];
# ...
switch ($comp) {
    case 'zstd':
        header("Content-Encoding: zstd");
        ob_start(function(&$data) use ($level) {
            return zstd_compress($data, $level);
        });
        break;
    case 'gzip':
        header("Content-Encoding: gzip");
        ob_start(function(&$data) {
            return gzencode($data);
        });
        break;
    case 'obgz':
        ob_start('ob_gzhandler');
        break;
    default:
        # nothing
}

readfile(__DIR__.'/war_and_peace.html');

So it basically only spits out what it's being asked for, by means of the ?compression parameter.

Test system (2024-Apr-01):

• Debian sid (6.7.9-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.7.9-2 (2024-03-13) x86_64 GNU/Linux)
• Apache 2.58
• PHP 8.3.4 (cli) (built: Mar 29 2024 05:24:33)
• PHP: Server API: FPM/FastCGI
• PHP zstd extension 0.13.3
• FPM is configured in a lousy wfm-style
• CPU: AMD Ryzen 7 5700G with Radeon Graphics (family: 0x19, model: 0x50, stepping: 0x0)

License

• Test document "War and Peace" licensed under the Project Gutenberg license.
• Code: MIT.

Copyright (c) 2024

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.