As different online speed test tools will have different results, the accuracy is questionable.
For non CentOS servers, please perform a quick network test from the Hong Kong Government.
URL: http://speedtest.ofca.gov.hk/index.html
Please proceed as follows:
1. Visit http://speedtest.ofca.gov.hk/index.html
2. Drop down to the bottom of the page and click on the button of "I accept and wish to continue"
3. Click on "Continue"
4. Click on "Start Test"
5. Screenshot and submit a support ticket to us with the test result for further inspection
For CentOS servers, please perform a quick network test from NixCraft.
URL: https://www.cyberciti.biz/faq/install-speedtest-cli-on-centos-redhat-fedoa-scientific-to-measure-internetspeed/