PHP accelerator for Moodle in TKL Moodle Appliance

I have been using a custom build of Moodle 1.9 on the TKL LAMP 11 build.  We use it extensivly in our classroom.    I recently setup the new 12.0 version of Moodle 2.3 in a vm.  

I am learning my way around the new interface but it strikes me how much slower it is than 1.9.   I looked around and one of the things I notice is there doesn't seem to be a php accelerator in the build. i.e. eAccelerator or APC.    As a simple test I tried doing a apt install of php-apc but it killed apache.

That doesn't really suprise me as I have encountered issues with other packages and TKL in the past. I am pretty all the LAMP based TurnKey web appliances should come with a php accelerator pre-integrated.    I wondered if anyone has experiance with this issue and or any sugguestions.