In this article:
When minifying assets, this consumes resources such as CPU and Memory, and may increase the time required to respond to HTTP requests for the minified content. Because of this, Minification should always be used with properly configured caching. In environments with limited resources, minification may have an adverse impact on general performance.
Choosing a Method for Minification
While multiple methods are available, you should almost always use disk-based caching unless you have a clear reason to do otherwise. In-memory caches are typically cleared more often, and because generating minified assets is costly this may have an adverse impact on performance.
W3 Total Cache
You haven't seen fast until you've tried PRO
Full Site CDN + Additional Caching Options
Advanced Caching Statistics, Purge Logs and More
Everything you need to scale your WordPress Website and improve your PageSpeed.