https://arstechnica.com/gadgets/2017/10/the-pixel-2-contains-a-custom-google-soc-the-pixel-visual-core/

Google's newest flagship smartphone, the Pixel 2, is nearly out. The company has been talking a big game about the 2's camera and calling it, definitively, "the best smartphone camera." But Google has been keeping a huge secret under wraps: the Pixel 2 has a custom, Google-designed SoC dedicated exclusively to camera image processing. The SoC is not active yet, but Google claims it will make the Pixel 2 process photos faster and more efficiently than ever.

In addition to the usual Qualcomm Snapdragon 835 SoC, the Pixel 2 is equipped with the "Pixel Visual Core," an extra, second SoC designed by Google with hardware-accelerated image processing in mind. At the heart of the chip is an eight-core Image Processing Unit (IPU) capable of more than three trillion operations per second. Using these IPU cores, Google says the company's HDR+ image processing can run "5x faster and at less than 1/10th the energy" than it currently does on the main CPU.