[LeEco Le 2 ROMs, Kernels, Recoveries, & Other Deve] twistyplain:
That's not over-clocking because big cores' stock speed is 1.8 and small cores max at 1.4. Kernels that overclock the CPU can only do a modest overclock because going higher will cause thermal issues.

There's a version of overload kernel that overclocks small cores' to 1483 but it doesn't overclock big cores. Truth is that over-clocking will cause the phone to overheat very quickly because the CPU uses 28nm fabrication process. The developer noticed that and immediately stopped over-clocking his later builds.

Your problem of not being able to get higher frequency is most probably because of thermal throttling. Gaming causes the CPU to heat up quickly so you must increase thermal throttling threshold slightly for sustained performance at higher clock speed before thermal throttling kicks in.

I play a lot of Real Racing 3 at max graphics and also some Modern Combat 5 and know a thing or two about this phone when it's pushed hard. The rule of thumb is DO NOT play games with big core maximum frequency set at 1.8 GHZ. Thermal throttling kicks in barely two minutes into the gaming session and knocks the big CPUs to 1113 MHz. Needless to say that's bad for games. To be safe, I recommend underclocking big cores to a maximum of 1.6 GHZ. Most games actually do well with just 1.2. Small cores do little during gaming and underclocking or over-clocking doesn't help during gaming. They're used a bit to help run the main menu. For big cores I almost always turn one off completely during gaming (more on that later). Do NOT play games with the phone's case attached and try to stay in a cool place while gaming.

Lagging audio doesn't have much to do with CPU speed. It's caused by I/O latency. That is delay between reading from internal storage and playing the sound (our phone has EMMC memory which is rather slow compared to UFS which is found in more expensive phones. Try to change your I/O scheduler to Maple if you have a Kernel that supports it. I recommend Omnystal_Kernel_v1.0 by Mr Darkness (Google it).

Also, CPU governor for small cores should prefferably be interactive. Don't use any energy saving governor during gaming. Governor for big CPU should be Bioshock if you install the kernel I mentioned. With maximum number of big CPU cores set at 3, Bioshock governor tries to stick to higher frequencies round-robin between the three active cores. That ensures that at least all cores get to rest for a few milliseconds as the three active ones do the heavy lifting. It helps with temps but nothing you'll notice outright. On this phone you must take every advantage to enable the phone to run cooler. If you don't have Bioshock for big cores use interactive at least. On demand might cause stuttering.

I have attached a thermal config file that should increase your throttling limit slightly. It should go to /system/etc. Replace the existing one and set permissions to 644 (rw-r--r--) and reboot. If you don't know what that is don't touch your system partition before you read about file permissions.

And hit the thumbs up button if it helps. Motivate me to keep helping because why else would I write such a long post? :confused: