HHVM 3.20, 3.21 and 3.22 are still faster than PHP 7.2 especially with many connections under load, however as of October 2017 there still are no official pre-compiled HHVM packages for CentOS 7.x so we need to revisit how to build it by hand, which is not too difficult, just takes most servers awhile to assemble
There are instructions on the HHVM wiki for CentOS7 but they are a year out of date now.
The process is straightforward, first we need to not only make sure we have all the libraries we need but also the development libraries and most recently a newer version of the GCC compiler, we will use GCC 6.3 found in the official SCL Devtoolset-6 for CentOS 7 (trusted because it is built by Redhat/CentOS)