What is the default Kernel Governor in Stock Samsung Galaxy Mega Android ROM? I have rooted my phone recently and just installed ROM Toolbox which has several Governors available. It is using OnDemand by default, but I switched to Interactive. I just need to be as close to default settings in order to maintain stability.

Btw, when I am using a third party app to change CPU Freqs, ROM Toolbox in this case, It seems to be a bit laggy. Is this normal?
I don't know the default governor for the Galaxy Mega. However, there's an easy way to determine your current governor. Rebooting the phone (Unless you ticked the option in ROM Manager and/or other apps to persist governor selections through reboot) will reset it back to its default setting.

You can find your current governor by running the following command in an adb shell or terminal emulator:

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Chances are your default governor is indeed ondemand. It is commonly used as the default governor on many Android devices, and seems like one that Samsung would like to use.