Could you please diagnose my bottleneck?

[TkSilver]

It is not Snapdragons specifically, but the Adreno graphics and even more specifically the drivers that were made for those GPUs. The OpenGL ES drivers on the 200 and 300 series were pretty bad. The CPU portion of the Snapdragon SoC are actually pretty good.... well better then most sans Tegra and sometimes Exynos.