Users of WordPress sites have lots of possibilities to increase site efficiency and make it work better. One of such options is W3 Total Cache (W3TC) plugin. How can it decrease site loading time two fold? There are some presumptions.
First of all, activate Page, Object, and Browser Caching, using W3TC plugin. It will reduce both latency and network traffic. Cash the most frequently opened pages (front page, SSL HTTPS requests, 404 error pages and pages for logged in users), enable HTTP compression, disable cookies for static files – all that may help. But remember that the same settings may have different impact on sites, so you should try and test them.
Thirdly, you may use a self-hosted CDN. It makes WordPress sites run faster by parallelizing downloads.