Is Codeigniter 3 php 7 ready?

the strange thing with our App is:
According to the profiler PHP 5.6.8 outruns PHP 7 
Our CI App is 10% faster with PHP 5.6.8

every controller or something like that takes about 10% longer.

i'm not sure what this is but in case of interest the tests ran with the following hardware components:
CPU: i7 5930k
RAM : G.Skill RipJaws 4x4 (3200)
MB: Gigabyte GA-X99 UD5 Wifi

Webserver: Apache 2.4.x (VC11)
DB: latest Mysql, MSSQL

After that, i've downloaded a benchmark script from php-benchmark-script.com (not sure if this is relevant, but the code looks not that bad, just running some functions) and the results were strange as you can see below:

--------------------------------------
|        PHP BENCHMARK SCRIPT        |
--------------------------------------
Start : 2015-11-11 20:43:09
Server : [email protected]
PHP version : 5.6.8
Platform : WINNT
--------------------------------------
test_math                 : 0.885 sec.
test_stringmanipulation   : 1.726 sec.
test_loops                : 0.539 sec.
test_ifelse               : 0.317 sec.
--------------------------------------
Total time:               : 3.467 sec.


--------------------------------------
|        PHP BENCHMARK SCRIPT        |
--------------------------------------
Start : 2015-11-11 21:09:52
Server : [email protected]
PHP version : 7.0.0rc6
Platform : WINNT
--------------------------------------
test_math                 : 0.274 sec.
test_stringmanipulation   : 1.952 sec.
test_loops                : 0.280 sec.
test_ifelse               : 0.213 sec.
--------------------------------------
Total time:               : 2.719 sec.

It might explain some things because, the stringmanipulation is about 10% slower on PHP7 than on PHP 5.6.x and we do that a lot.
But shouldn't PHP7 be up to twice as fast as PHP 5.6. ?