What type oh PHP accelerator?

@VeNoM

eAccelerator like APC are opcode caches. APC also provides a userland cache. However, recent PHP versions (>=5.5) come with OPcache. For older versions (PHP >=5.2 but < 5.5), there is a PECL extension available). Note that OPcache is only a opcode cache. If you also need an userland cache, you'll have to also install APCu which is like APC without the opcode cache layer.

I would recommend to go with OPcache and APCu. All others are not working with recent PHP versions.