This is how Google built the Tensor G5 without Samsung

It is no secret that the upcoming Google Tensor G5 inside the Pixel 10 series will be special — unlike all the current chips in the series, it will be built without Samsung’s help. We know that the chip will be built using TSMC’s 3nm-class process node and have had a good look at its core specs, but not much more than that. Building an entire SoC from scratch is a monumental task, which raises a question: how did Google, a relatively new company in the chip business, do it?

Thanks to a source inside Google, Android Authority has learned previously unknown Tensor G5 specs, giving us a unique insight into how it was created.

Obviously, the most important parts of a modern SoC are the CPU and GPU. As we knew previously, Google has opted to license the Arm Cortex CPU cores, the same as those used in the Samsung-built Tensor chips. Unlike the previous chips, however, Google has picked a new IMG DXT GPU, replacing the Arm Mali graphics parts used in Tensor so far.

The previous Tensor chips had some Google-designed IP blocks that have been carried over to the Tensor G5. The audio is processed on the “AoC” — “always-on compute,” a custom-built audio DSP first introduced in the original Tensor. The same goes for the “Emerald Hill” memory compressor.

Another noticeable thing that was carried over was the TPU. AI capabilities are one of the main justifications for why Tensor exists in the first place, so it isn’t surprising that Google brought it (or at least an evolved version) to the Tensor G5. Similarly, the “GXP” DSP, Google’s design built around licensed Tensillica Xtensa cores, was brought to the G5 to help with specific workloads, including image processing.

This is where things start deviating from past generations — previous Tensor chips used a combination of two video codecs: Google’s “BigWave” AV1 codec core and Samsung’s MFC (Multi Format Codec) for the other formats. It would seem logical for Google to use something built in-house, perhaps even for all the formats, but that’s not the case. Instead, Google uses third party IP to handle all the formats. Specifically, the core used is Chips&Media’s WAVE677DV, spec’d to handle up to 4K120 encoding and decoding in AV1, VP9, HEVC and H.264.

Google has also decided to license a 3rd party display controller and 2D GPU. The core used is VeriSilicon’s DC9000. The previous Tensor chips used fully standard Exynos DPUs for this purpose.

Of course, cameras are one of the Pixel’s most important features, and Google has been working on building custom ISP hardware since the first Tensor chip. The previous chips only had a few custom Google-designed blocks to complement the regular Samsung ISPs, but that changes now. The Tensor G5 will have a fully custom ISP from the front-end to the back-end parts of the pipeline.

Google has custom-built built a few foundational parts for its chips, like a memory controller, system-level cache (GSLC), and clocking/power modules. That’s where Google’s involvement ends, however. The other parts of the chip, including many basic interfaces like USB, PCIe, I3C, as well as the physical layer controllers (PHYs) for interfaces like DSI (display), DisplayPort, and memory (LPDDR5x) are all licensed from various IP providers, mostly Synopsys.

However, this isn’t an uncommon practice — some of these exact cores were even used by Samsung! This is because building and verifying IP is a costly endeavor with the potential for things to go wrong. It simply doesn’t usually make sense to build something that will only fulfill standard functions (like is the case with controllers for interfaces) when proven versions built by other companies can be licensed. Obviously, this limits flexibility, but in many cases, that’s an acceptable trade-off.

Even though Google’s Tensor G5 bids farewell to Samsung, it shows why the partnership was the right choice in the first place. Even years after first setting out with Tensor, Google still has to rely on 3rd party IP for most of its interfaces and functions. Besides the fact that it will be built on TSMC’s process, the Tensor G5 won’t be all that different from the previous Tensor chips. It still only has certain bits and pieces by Google, whereas the rest is generic and built by someone else, with the minor difference of who that someone is.

The partnership with Samsung has allowed Google to test and develop its own IP way before it was ready to use its own foundation for the chip, and now it’s finally mature enough to be on its own. I can’t wait to see how the future Tensor chips will evolve with the fundamentals now in place.

The Google Tensor G5 will arrive in the Pixel 10 series, launching later this year.