create phprc, use the ftp user access, go to php version and add the ff:

;
{
  {
    {
      The following lines were automatically added by DreamHost
      zend_extension = opcache.so
      memory_limit = 500 M
      upload_max_filesize = 128 M
      post_max_size = 256 M
      max_execution_time = 500
      max_input_time = 500
      max_input_vars = 5000

      ;
    }
  }
}
That 's all from DreamHost

then restart settings go to Domain Management
Click the domain
click Change Settings Wait 5 minutes