PHP 8.4 vs 8.3 vs 8.2 Performance: Does every upgrade get faster?

[00:00] With every new release of PHP, you

[00:02] probably ask yourself, is there an

[00:04] automatic gain in performance just by

[00:07] upgrading? This is what I asked myself

[00:09] when PHP 8.4 came out and put my team at

[00:12] Tideways to work on a benchmark to

[00:14] answer once and for all. The results are

[00:17] now published on our blog, and I want to

[00:20] discuss them in this video. The main

[00:22] result, upgrading to PHP 8.4 four will

[00:26] not magically increase the performance

[00:28] of your PHP application to noticeably

[00:31] better

[00:32] levels. In fact, our benchmarks show

[00:35] that during the PHP8 series, not a

[00:38] single release improved the performance

[00:41] noticeably. That means PHP 8.4, 8.3, 8.2

[00:45] are almost virtually the same

[00:48] performance. This was quite a surprise

[00:50] to me. The reason is that previous

[00:53] benchmarks by others showed that there

[00:57] was a noticeable small improvement

[00:59] across uh the different

[01:02] versions. Specifically, this uh PHP

[01:05] benchmarks post that was widely cited

[01:08] across the community showed increases of

[01:12] a few% between uh the different PHP 8.1,

[01:16] 8.2, and 8.3 versions.

[01:18] In our benchmark, we were not able to

[01:20] replicate these improvements. For our

[01:23] benchmark, we set up two test scenarios

[01:25] that each ran for 60 seconds, including

[01:28] warm-up periods. First, we measured the

[01:31] response times by sending a fixed number

[01:35] of

[01:36] requests. Second, we measured the

[01:38] requests per second by sending as many

[01:41] requests as possible during the time

[01:43] period.

[01:45] We did this against three widely spread

[01:48] frameworks. A Symfony demo application,

[01:51] a Laravel demo application, and a

[01:53] WordPress demo application. You can find

[01:56] more details on our methodology on the

[01:58] blog post, including the code to set up

[02:00] the benchmarks, uh the specifications of

[02:03] the machine we used and the versions of

[02:06] all the different software that we

[02:07] benchmarked against. Let's look at the

[02:10] results starting with

[02:12] Symfony. As you can see, for the tests

[02:15] sending 100 requests per second, the

[02:18] response times across the versions PHP

[02:20] 8.2, 8.3, and 8.4 did not noticeably

[02:25] change. The average median 95, and 99

[02:29] percentile are virtually the same.

[02:31] Looking at the test with 15 concurrent

[02:34] users attempting to send as many

[02:36] requests as possible, we also see that

[02:38] for PHP 8.2, 8.3, and 8.4, for the

[02:42] number of requests is almost the same at

[02:47] 538. We see the similar results for the

[02:50] Laravel demo application across PHP 8.2

[02:53] to 8.4 for all the metrics average

[02:56] median 195 and 99 percentile. The

[03:00] response times are almost the same

[03:02] signaling that the performance did not

[03:04] really change for the test sending as

[03:07] many requests as possible for 60

[03:09] seconds. The Laravel demo application

[03:12] achieved around 1,020 requests per

[03:15] second regardless of the PHP version

[03:18] 8.2, 8.3 or 8.4. So the performance here

[03:22] again almost the

[03:26] same. We also picked WordPress because

[03:29] it's possible to install it on such a

[03:32] wide range of PHP versions that we are

[03:35] able to test it from PHP 7.4 to

[03:38] 8.4. Again, throughout the PHP8 series,

[03:42] there's not really a visible change in

[03:44] performance. However, from PHP 7.4, it

[03:48] seems the performance increased slightly

[03:51] to

[03:52] PHP8. We can see this here that the

[03:55] response times for 100 requests per

[03:57] second slightly decreased by a few

[04:00] milliseconds from uh PHP 7.4 to uh 8.2

[04:04] and following versions.

[04:09] This change is much more visible for the

[04:12] scenario where we send 15 concurrent

[04:15] users to uh perform as many requests as

[04:17] possible for 60 seconds. For PHP 7.4,

[04:21] the WordPress installation achieved 206

[04:25] requests per second and a 5% roughly 5%

[04:29] higher number for all the PHP 8.2, 8.3,

[04:33] and 8.4 four versions with around 220

[04:37] requests. This at least shows that there

[04:39] is some improvement from PHP 7 to PHP 8,

[04:43] but it also cements that the performance

[04:46] in P the PHP8 series really didn't

[04:49] change a lot just by upgrading the

[04:51] version. With these results, I ask

[04:54] myself what the future for PHP

[04:56] performance holds.

[04:58] First, the Zen virtual machine seems to

[05:00] be at the end of the potential

[05:02] improvements that we see. The next

[05:05] versions will not radically increase the

[05:07] performance anymore. Second, we can see

[05:11] improvements in specific PHP APIs across

[05:14] the latest versions. So, for example,

[05:17] the new DOM document HTML 5 support has

[05:20] a lot of performance improvements. We

[05:23] have the sprintf improvements and also

[05:25] improvements to various APIs and

[05:27] functions. So if you want to invest some

[05:30] time in your application, you can

[05:32] improve it the performance by using more

[05:35] modern and faster

[05:37] APIs. Third, we haven't really seen much

[05:41] performance improvements by the just in

[05:43] time compiler that uh PHP now has for

[05:46] web applications. the performance

[05:48] difference is really not measurable and

[05:50] we will see if there's maybe an

[05:52] improvement to the uh JIT in the future

[05:54] that will level up the performance of

[05:56] PHP to a new level. In conclusion, your

[06:00] application architecture, code, and

[06:02] algorithms are probably the most

[06:04] important puzzle piece in improving the

[06:07] performance of your application going

[06:09] forward. You can find a few ideas on how

[06:12] to improve PHP performance on this

[06:13] YouTube channel, and we'll add a new

[06:15] video every week. Don't miss out by

[06:18] subscribing to this channel. See you

[06:20] around. Bye.