A custom eight-core Image Processing Unit (IPU) is sitting idle inside the new Google Pixel 2 phones, just waiting for Android 8.1 to wake it up. Google already claims that the Pixel 2 cameras are the best on any smartphone, so the fact that a Google-designed SoC will soon dedicate itself to image processing is an exciting prospect. Google says that photos will process faster and more efficiently when the SoC is switched on, making the best camera even better. This isn’t just a software update, but a true hardware addition.
Joining the Snapdragon 835 SoC in the Pixel 2 phones is a second SoC, the “Pixel Visual Core” for hardware accelerated image processing. The chip’s eight-core IPU can perform 3 trillion operations in one second, which will allow HDR+ image processing to run five times faster and use less than 1/10 the power as before.
Unfortunately, Google launched the phones with the custom SoC disabled, but the Android 8.1 Oreo developer preview should switch it on. This will also open up HDR+ processing to third-party apps, allowing them to match the quality of the native camera. Google also sees an expanding future for the Pixel 2’s chip, claiming that the Pixel Visual Core “will handle the most challenging imaging and machine learning applications” and “we’re already preparing the next set of applications.”
Having a second custom SoC is definitely unusual and for the moment requires some innovative workarounds. With a Snapdragon 835 SoC already installed, Qualcomm won’t allow integration of additional chips. Google had to use a minimal SoC to surround its eight-core IPU and then connect it to the main SoC. To break this down, the Pixel Visual Core has a single Cortex A53 core CPU to “regulate traffic” and its own DDR4 RAM, along with a PCIe line that likely acts as a bus to the rest of the system. It’s not an optimal setup, which would have just one SoC integrating the IPU next to the GPU (the co-processor), but Google would have to build its own competing silicon for that to happen.
Rumors of Google wanting to design and build its own SoCs have been circulating for a couple of years, including processors designed for both AR and VR. The Pixel Visual Core could very well be the first step to Google taking on Qualcomm. It’s kind of strange that such a major hardware addition was never mentioned during Google’s Pixel 2 event, but hopefully this little secret weapon will soon give a boost of adrenaline to an already outstanding camera.
Source: Ars Technica