Google's Tensor inside of Pixel 6, Pixel 6 Pro: A Look into Performance & Efficiency
by Andrei Frumusanu on November 2, 2021 8:00 AM EST- Posted in
- Mobile
- Smartphones
- SoCs
- Pixel 6
- Pixel 6 Pro
- Google Tensor
Conclusion & End Remarks
Google’s newest Pixel 6 and 6 Pro are definitely most interesting devices, as in many ways they represent Google most competitive and value-rich phones the company has been able to make in years. While today’s article isn’t focusing on the device itself – more on that in a later review, including more in-depth camera coverage, what we did have a deeper look today was at the new chip powering the phones, the new Google Tensor.
The company notes that the primary reason they saw the need to go with a customized silicon approach, was that current merchant silicon solutions didn’t allow for the performance and efficiency for machine learning tasks that the company was aiming for in their devices. This performance and efficiency is used to enable new use-cases and experiences, such as the many ML features we see shipped and demonstrated in the Pixel 6 series, such live transcribing, live translation, and image processing tricks, all that run on the Tensor’s TPU.
While Google doesn’t appear to want to talk about it, the chip very clearly has provenance as a collaboration between Google and Samsung, and has a large amount of its roots in Samsung Exynos SoC architectures. While yes, it’s a customised design based on Google’s blueprints, the foundation means that some of the defining characteristics of Exynos chips is still found on the Tensor, particularly power efficiency is one area of the SoCs that are very much alike in, and that also means that the Tensor falls behind, much like the Exynos, against Qualcomm’s Snapdragon solutions when it comes to battery life or efficiency.
Google’s CPU setup is a bit different than other SoCs out there – a 2+2+4 setup with X1 cores, A76 cores and A55 cores is unusual. The two X1 cores are fine, and generally they end up where we expected them, even if there’s a few quirks. The A76 cores, ever since we heard those rumours months ago that the chip would feature them, made no sense to us, and even with the chip in our hands now, they still don’t make any sense, as they clearly fall behind the competition in both performance and efficiency. Who knows what the design process looked like, but it’s just one aspect of the chip that doesn’t work well.
GPU performance of the Tensor seems also lacklustre – while it’s hard to pinpoint wrong-doings to the actual SoC here, Google’s choice of going with a giant GPU doesn’t end up with practical advantages in gaming, as the phones themselves have quite bad thermal solutions for the chip, not able to properly dissipate the heat from the chip to the full body of the phones. Maybe Google makes more use of the GPU for burst compute workloads, but so far those were hard to identify.
So that leads us back to the core aspect of the Tensor, the TPU. It’s the one area where the SoC does shine, and very clearly has large performance, and likely also efficiency advantages over the competition. The metrics here are extremely hard to quantify, and one does pose the question if the use-cases and features the Pixel 6 comes with were really impossible to achieve, on say a Snapdragon chip. At least natural language processing seems to be Google’s and the Tensor’s forte, where it does have an inarguably large lead.
One further aspect that isn’t discussed as much is not related to the performance of the chip, but rather the supply chain side of things. We of course have no idea what Google’s deal with Samsung looks like, however both new Pixel 6 phones are devices that seemingly are priced much more aggressively than anything we’ve seen before from the company. If this is related to the SoC bill of materials is just pure speculation, but it is a possibility in my mind.
In general, I do think Google has achieved its goals with the Tensor SoC. The one thing it promises to do, it does indeed do quite well, and while the other aspects of the chip aren’t fantastic, they’re not outright deal-breakers either. I still think energy efficiency and battery life are goals of highest priority in a design, and there we just absolutely need to see better improvements in the next generation Tensor. We don’t know what path Google is taking for future designs, but it’ll be interesting to see.
We’ll be following up with a more in-depth review of the actual Pixel 6 phones, starting with a camera-focused article – stay tuned.
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melgross - Wednesday, November 3, 2021 - link
Apple couldn’t integrate Qualcomm’s modems in their own chips because Qualcomm doesn’t allow that. They only allow the integration of their modems into their own SoC. It’s one reason why Apple wasn’t happy with them, other than the overcharging Qualcomm has been doing to Apple, and everyone else, by forcing the licensing of IP they didn’t use.ChrisGX - Thursday, November 4, 2021 - link
Yes, but all that conjecture hasn't been confirmed by any reputable source. And, the statements by Phil Carmack and Monika Gupta indicate Google has been optimising for power (most of all) and performance (to a lesser degree) rather than area. We end up back at the same place, using the A76 cores just doesn't make a lot of sense.Also, the A78 is perhaps 30% larger than the A76 (on a common silicon process) whereas, I think the X1 is about twice the size of the A76. I'm not sure what the implications of all that is for wafer economics but I'm pretty sure the reason that Tensor will probably end up suffering some die bloat (compared to upper echelon ARM SoCs from past years) despite the dense 5nm silicon process is the design decision to use two of those large X1 cores (a decision that Andrei seems perplexed by).
Raqia - Tuesday, November 2, 2021 - link
The Google TPU only trades blows with the Qualcomm Hexagon 780 with the exception Mobile BERT. It's not an especially impressive first showing given that this is Google's centerpiece, and it's also unclear what the energy efficiency of this processor is relative to the competition. It's good there's competition though; at the phone level, software is somewhat differentiated and pricing is competitive.webdoctors - Tuesday, November 2, 2021 - link
Even if the performance isn't impressive, the big deal is guaranteed SW updates. Look at the Nvidia Shield, it came out in 2015 and its still getting the latest Android updates/OS! No other product has been updated for so long, 6 YEARS!Now that Google owns the SoC they have full access to the SoC driver source code so should be able to support the SoC forever, or at least ~10 years....not reliant on Qualcomm's 3 yr support term etc.
BlueScreenJunky - Tuesday, November 2, 2021 - link
Yeah, except they only guarantee 3 years of software update and 5 years of security updates, which is really a shame if you ask me.If they could have guaranteed 5 years of OS updates from the start it would have been a very strong selling point. Especially since the difference between each generation becomes smaller every year, I could see people keeping a Pixel 6 for well over 3 years... How cool would that be to keep a $599 for 5 years and still run the latest android version ?
webdoctors - Tuesday, November 2, 2021 - link
I agree: https://support.google.com/pixelphone/answer/44577...They should've just guaranteed 5 years for SW updates. Based off the pixel 3 being guaranteed for 3 yrs and than this month dropping security updates for Pixel 3 from their list, they're serious about guaranteeing being the maximum support they'll provide which is unfortunate. Maybe they'll update it this year cause that seems like a big hole.
TheinsanegamerN - Tuesday, November 2, 2021 - link
Why? What new features do you NEED in your phone? Android stopped evolving with 9, iOS with about version 11. The newest OSes dont do anything spectacular the old ones didnt do.You're getting 5 years of security updates and dont have apps tied to OS version like apple, giving the pixel a much longer service life then any other phone.
tipoo - Tuesday, November 2, 2021 - link
They're saying 3 years of OS updates, a far shot from 10. 5 years of security updates, which is a start, but owning their supposed own SoC they should have shot for 5 of OS.BillBear - Wednesday, November 3, 2021 - link
After all the build up on "We're going to have our own chips now so we can support them without interference from Qualcomm", three years of updates is seriously underwhelming.Apple has six year old phones running the current OS and the eight year old iPhone 5s got another security update a month ago.
Google needs to seriously step up their game.
melgross - Friday, November 5, 2021 - link
All we know now about software updates is that it will get five years of SECURITY updates, nothing about OS updates was stated, as far as I see. If that’s true, they Google may still just offer three years. Even now, Qualcomm allows for four years of OS updates, but not even Google has taken advantage of it. So nothing may change there.