A problem was experienced with the Swift Performance Lite caching plugin over the past week. Whenever a plugin was activated or deactivated, the Swift Performance Lite plugin would crawl the entire site, cluttering up the statistics in the security plugin. This also occurred at night, when the site was unattended.
In all, it appeared as though Swift Performance Lite crawled the site about a hundred times a day.
(Initially, this behavior was mistaken for an external bot coming from Siteground Hosting since its hostname was given as XXX.YYYYY.siteground.us. However, blocking this hostname resulted in frequent crawling attempts from WP-CRON.PHP — a cron job most likely caused by a plugin.)
Although it was always my intention to compare page load speeds of Swift Performance Lite with W3 Total Cache, the discovery of this issue gave this comparison test a high priority.
The two caching plugins were therefore tested 36 times to gauge their effect on site speed. (Both were tested with Siteground’s Static Cache running in the background.)
Methods
Each test was performed using Pingdom.com’s Website Speed Test, using the San Jose, California location option. Each test was conducted with the HTTP URL rather than the HTTPS URL.
In all, 9 tests were run each day for 4 days. Load time results were recorded, and averaged at the end of the study.
Results
The following HTML tables were generated by the Tableizer Excel to HTML conversion site:
Table 1. Page Load Speed with Swift Performance Lite vs. W3 Total Cache
| Date | Time | Load Time with Swift Performance Lite (sec) | Load Time with W3 Total Cache (sec) |
|---|---|---|---|
| 9/5/2018 | 15:04 | 1.070 | 0.861 |
| 0.904 | 1.040 | ||
| 1.030 | 1.060 | ||
| 17:09 | 1.050 | 1.130 | |
| 1.060 | 1.190 | ||
| 1.890 | 1.090 | ||
| 19:40 | 1.270 | 1.770 | |
| 1.250 | 1.220 | ||
| 1.090 | 0.975 | ||
| 9/6/2018 | 13:46 | 1.140 | 1.150 |
| 1.150 | 1.160 | ||
| 1.070 | 0.888 | ||
| 16:57 | 0.927 | 1.150 | |
| 0.967 | 0.860 | ||
| 1.090 | 1.150 | ||
| 19:14 | 0.959 | 0.849 | |
| 1.020 | 0.994 | ||
| 1.130 | 0.994 | ||
| 9/7/2018 | 17:16 | 0.962 | 0.873 |
| 0.945 | 0.899 | ||
| 1.060 | 0.906 | ||
| 18:58 | 0.958 | 1.100 | |
| 1.080 | 0.873 | ||
| 0.976 | 1.120 | ||
| 20:44 | 1.110 | 1.140 | |
| 1.090 | 1.120 | ||
| 0.902 | 0.866 | ||
| 9/8/2018 | 10:21 | 0.958 | 0.910 |
| 1.110 | 1.210 | ||
| 1.070 | 0.951 | ||
| 13:36 | 0.911 | 1.080 | |
| 0.994 | 0.887 | ||
| 0.954 | 1.110 | ||
| 16:02 | 0.967 | 0.872 | |
| 1.100 | 1.070 | ||
| 1.050 | 1.130 | ||
| n | 36 | 36 | |
| Average | 1.063 | 1.046 | |
| Std Dev | 0.168 | 0.173 |
Table 2. Pingdom Grades for Swift Performance Lite vs. W3 Total Cache
| Performance Factors | Swift Performance Lite | W3 Total Cache |
|---|---|---|
| Overall Grade | A (91%) | B (88%) |
| Combine External JavaScript | D (61%) | F (44%) |
| Combine External CSS | B (80%) | B (86%) |
| Minimize DNS Lookups | B (87%) | B (88%) |
| Leverage Browser Caching | A (92%) | B (80%) |
| Remove Query Strings | A (92%) | B (87%) |
| Specify A Cache Validator | A (100%) | A (95%) |
| Serve Static Content fr. Cookieless Domain | A (100%) | A (97%) |
Table 1 shows that the Swift Performance Lite caching plugin yielded slightly slower page load speeds than W3 Total Cache (1.063 sec vs. 1.046 sec). Although the 0.017 second difference may not be significant, at the very least it appears that the two caching plugins are at least comparable in their effect on page load speeds.
Table 2 shows that Pingdom.com gave Swift Performance Lite slightly higher letter & numerical grades than W3 Total Cache (A vs. B; 91% vs 88%). It also granted Swift Performance Lite higher grades for a variety of scoring factors.
Despite this apparent advantage, Swift Performance Lite was still still slightly slower than W3 Total Cache.
Conclusions
An alternative to Swift Performance Lite was sought because this plugin tended to clutter up the statistics by excessively crawling the site during cron jobs. Since page load speeds with W3 Total Cache were determined to at least as fast as Swift Performance Lite (and possibly faster), W3 Total Cache will be used as the caching plugin on Ancient Greek Keyboard from now on.
It should be mentioned that W3 Total Cache sometimes breaks CSS styles, so it is anticipated that some of the site’s styles will have to be given greater priority (either through use of the !IMPORTANT property or by using greater specificity in CSS rules).
UPDATE (Sep 10, 2018): W3 Total Cache activated on site. As expected, this plugin broke link and header styles. This could not be fixed with the !IMPORTANT property, so the CSS Minify setting was disabled.
After this was done, Swift Performance Lite was deleted from the site.
Other posts in this series:
- Siteground Speed Test (With & Without Static Caching)
- Speed Test of Swift Performance Lite plugin
- Caching Plugin Speed Tests: Swift Performance Lite vs. W3 Total Cache
- Speed Test: W3 Total Cache With Autoptimize
- Speed Test of WP-Rocket plugin (default settings)
- Speed Test of WP-Rocket plugin (additional settings)
- WP Rocket Speed Test (with & without SiteGround Static Caching)
