> Because it's very wasteful to keep reinterpreting the same page every time, as opposed to just running it in RAM from a warm JIT.
You are running it from RAM. PHP's OPcache, and HHVM, will both compile the code only once (well, HHVM will compile it multiple times due to JIT, but it only touches the disk once) and cache it.
You are running it from RAM. PHP's OPcache, and HHVM, will both compile the code only once (well, HHVM will compile it multiple times due to JIT, but it only touches the disk once) and cache it.