Originally Posted by mobilequest
I too bought a S4 just three days ago. I knew that that the touchwiz-ui is laggy, it didn't bother me but I really thought the hardware would be good enough to run recent games lag-free. I was wrong.
Small games like subway surfers or temple run run smoothly but bigger games like Real Racing 3 lag and stutter. I am currently on stock rom with android 4.3, does it still lag with 4.4.2 google edition roms or aosp roms?
I did not have game performance issues with the 4.2 stock ROM back then, but IDK about stock 4.3.
Some AOSP-ROMs are slower in games than stock, others are faster. It also depends on the Kernel you are using of course.
A really fast ROM is broodplank's AOSP from source, you can find it in the i9505 original Android development thread. I am using it with broodplank's stock Kernel and changed some options via the broodparts-app.
I am very satisfied with its performance and stability, so you can give it a try. It is pure AOSP, though, so you lose all TW features. With XPOSED/Gravitybox, you can add some customizing features, which is enough for me. Some other features like iView and multiwindows are gone, but I don't really miss them.
But of course your requirements could be different, so you have to find out what's best suited for you by trying it out.