PrestaSpeed optimize your Prestashop database, images, some modules and configuration to increase the front office and back office access speed, and free space on disk.
https://codecanyon.net/item/prestashop-presta-speed-image-optimization/9199999
Didn't test on 1.7.6.4 yet.
https://codecanyon.net/item/prestashop-presta-speed-image-optimization/9199999
Didn't test on 1.7.6.4 yet.