how to keep the fps stable on mac

[retro gamerR]

Hi everyone don't know if anyone can help but i really need some assistance. i'm currently running the pcsx2 1.5.0 on my mac laptop ( macbook pro (Retina, 13-inch, late 2013) / processor: 2.4 GHz intel Core i5 / Memory: 4 GB 1600 MHz DDR3 / Graphics: intel Iris 1536 MB ) 

I've done everything i can to  increase the performance of the games, the games are running at 60 fps but fps will randomly drop down to 30 before going back up to 60. i would happy be happy to play at a lower fps if that means they would be more consistence when they are running.

Basically i was just wondering if anyone could help me get the games running as smooth as possible. In a perfect world i would just like to play with no lag 

[cantona]

Please post the contents of the emulog.txt file after the problem occurs. The file can be found in "My Documents\PCSX2\logs" for the installer version or in "PCSX2\logs" for the portable/binary version.

[jesalvein]

Please post the contents of the emulog.txt file after the problem occurs. The file can be found in "My Documents\PCSX2\logs" for the installer version or in "PCSX2\logs" for the portable/binary version.

Please make sure to enclose your emulog in code tags like so (remove the empty space on the closing code tag!):
[code]
Pasted emulog goes here
[ /code]