Snapdragon 820 also known as MSM8996 is based on Hydra CPUs and it should bring 35 percent of performance increase over the A57 / A53 based Snapdragon 810. Since Snapdragon 820 is 14nm there is a lot of room for performance increases in smaller transistors, higher clock and custom based cores.

The new GPU is known as the A530 and you can expect close to 40 percent of performance increase over the Adreno 430. The new GPU shares a virtual memory that should prepare it well for HSA compute and its supporting software.

There is a big focus on the improved camera and video performance. According to leaked slides the new PGU supports 4x60 decode with 4k60 FPS Miracast streaming 2.0.  There is HEVC 10 bit and VP9 decode support as well as Vesa DSC 1.1 compression with HDMI 2.0 at 4K60FPS.

Camera CPHY has higher throughput and lower power and the new DSP with Q6x60 825MHz + 2XHVX for camera differentiation. It comes with four times power improvement with lower power sensor.

It appears to be a quad core chip with an integrated modem. The modem supports 2XCA to 450Mbps with FDD/TDD UL CA (Category 10) which is the latest and greatest in LTE/4G modem technology.