PrestaShop Optimization Guide
The first step when optimizing PrestaShop is to make sure that you use the latest version of PrestaShop (and at least 126.96.36.199 or newer) which support PHP 7.
Using PHP7 with opcode caching (available by default with our Linux Shared Hosting plans) will give you an extra boost in performance right from the start.
If you can't use the latest version of PrestaShop or you need to use release older than 188.8.131.52 we recommend that you use at least PHP version 5.5 or 5.6 with opcode caching enabled (available by default with our Linux Shared Hosting plans).
If you are using other packages, such as VPS/Cloud we recommend that you look into the PHP version, and opcode caching. If you are using cPanel/WHM you can re-compile your EasyPache to use latest PHP version and opcode caching following the tutorial at: