Recently we decided to upgrade our WordPress core to version 3.7.1 and we figured we would perform some tests to see how the change affected us. I took our baseline of 11 performance tests (using webpagetest.org) and a single load test (using LoadStorm) to compare to our new set of data after upgrading to the new version. It was fun to see how things would perform, but the results were not shocking. There was virtually no difference between the performance tests. The page load time was on average 1.22% slower, and we’re talking tiny fractions of a second so the difference is indistinguishable to a human being. However, the percentage change could be noticeable on a slower site.
Our load test data was a little more interesting although a bit less thorough since we’re only comparing one test to another. The results were still quite similar, but we had a bit more variance on the HTML requests. The response average was nearly a half a second slower for the HTML pages, but the other measurements were reasonably close to one another for the HTML pages. For non-HTML requests we saw some errors due to timeouts and an increase in requests per second. The average response times were a tenth of a second slower.
In conclusion, the minuscule differences showed hardly any changes from the older version to the upgrade. Without knowing the full details of the changes that came with the new version the performance results make it appear that there were not many changes that would improve page performance. All in all WordPress is a solid content management system which you can have running very fast with a plugin and a few changes. See our earlier post about the W3 Total Cache plugin and how it helped our site’s performance and scalability through page caching.
If you’re interested in seeing the full set of test results you can view them from this PDF.