Smartphone processors are in a great place these days. Flagship smartphones offer more performance than you’ll ever need for browsing the web, checking email, and unfriending people on Facebook. You can even get great performance at the inexpensive mid-range price point too.
When it comes to the yearly chip announcements and new devices heading our way in 2020, smoother CPU performance isn’t going to offer that wow factor it once did. We’re quickly closing in on that point of diminishing returns. Chips will appear on slightly improved 7nm+ fabrication processes, meaning smaller efficiency gains compared to the previous generation. We’ll have to wait a little longer for 5nm EUV.
There are some more interesting trends on the horizon though, which could make 2020 a very exciting year for mobile processors.
Mobile graphics has room for improvement
We rigorously benchmark smartphones as part of our review process and one area where there’s still room for some noticeable improvements is in graphics performance. This is true across the board, with low-end processors that fall far behind today’s flagships, and flagship models that could still pack in more high-performance graphics silicon.
The growth in the market for gaming phones and the success of the mobile chip-powered Nintendo Switch suggests that there’s an appetite for high-fidelity gaming on the go. Qualcomm has even launched enhanced gaming versions of some of its chips, such as the Snapdragon 730G. But really what’s needed is more silicon area dedicated to graphics, along with power-efficient core designs to keep battery consumption under control.
We saw 20 percent gains from Qualcomm’s move from the Adreno 630 to 640 with the Snapdragon 855 and a huge 3.5x gains with Snapdragon 8xc and its bigger Adreno 690 GPU. Speaking of which, take a look at the die shots below to see that GPU silicon doesn’t even account for a quarter of the total silicon space inside modern phone SoCs.
For comparison, Nvidia’s Tegra line-up of chips dedicated significantly more space to the GPU. The latest Tegra Xavier chip for the machine learning market is basically one-third GPU. Of course, this chip isn’t efficient enough for smartphones and lacks many of the silicon features we’ve come to depend upon in smartphones. The 8cx is also too big and powerful for a smartphone use case. But in the future, the combination of more efficient 5nm manufacturing, larger batteries, and more efficient core designs could allow for SoCs to use bigger pools of GPU silicon for better performance.
Finally, Samsung and AMD signed a deal in 2019 to use AMD’s RDNA architecture in future mobile chip designs. The deal references AMD’s post-Navi micro-architecture, so it won’t appear in an Exynos chip until 2021 or 2022. But it is a sign that mobile chip manufacturers are increasingly looking at the full range of options on the market to eke out a competitive or cost advantage.
A dedicated chip for gaming phones sound like a pipedream, but demand appears to be growing.
More specialist silicon
As we’ve alluded to, the mobile SoC market is increasing dedicating silicon space to new heterogeneous computing components to boost performance while maintaining energy efficiency. Qualcomm’s Hexagon DSP takes up a notable amount of silicon space, as do the NPUs found inside flagship Exynos and Kirin SoCs.
We can see this trend in the above die shots, with a smaller percentage of silicon area reserved for the CPU and GPU in the Exynos 9820 compared to the 9810. This is partly due to the introduction of a bigger NPU, but also camera image processors, video encode/decode hardware, and 4G modems. All these components vie for precious silicon space in the name of increasing power efficiency for the most common smartphone tasks.
The traditional CPU and GPU now vie for die space with the ISP, DSP, NPU, and more powerful modems. This trend is likely to continue.
Next-generation SoCs will almost certainly continue down this path. More and more silicon space is likely to be used for more powerful machine learning capabilities. Chip manufacturers are increasingly turning to in-house machine learning designs as they narrow down the most common use cases, resulting in a wider range of capabilities coming to 2020 flagship phones.
Next year will also see more powerful image processors that are able to handle 4K slow-motion video and 100-megapixel cameras, and more enhanced networking components for blazing-fast Wi-Fi 6 and 5G modems.
Simply put, mobile chips have moved well beyond simple CPU/GPU designs and are becoming increasingly complex.
Integrated 4G/5G modems
With 5G networks whirring up across the globe, it would be very surprising if next-generation flagship SoCs didn’t ship with integrated 4G/5G multi-mode modems. Each major chip designer already has its own standalone 5G modem, after all. There’s Qualcomm’s Snapdragon X55, Samsung’s Exynos 5100, and Huawei’s Balong 5G01 or 5000. Work is also underway developing next-gen integrated modems for 2020 smartphones.
Next-gen 5G flagship chips are a given to hit the market, although cheaper 4G-only models could appear for specific regions. What’s more interesting is whether or not we’ll see integrated 5G modems make their way to mid-tier chipsets as early as 2020. Nokia is planning an inexpensive 5G phone, and it will be interesting to see what chipset the company opts for.
Alternatively, mid-range smartphones may simply pair up cost-effective chipsets with external 5G modems in relevant markets. The MediaTek M70 5G and Exynos 980 show promise for more affordable 5G handsets. The Samsung Galaxy A90 5G is hopefully just the first example of 5G phones without the typical flagship pricetag.
Bigger CPU cores
We’ve gone this whole article without mentioning CPU cores, partly because CPU performance is already more than adequate. But that doesn’t mean interesting changes aren’t on the way.
Current-generation SoCs saw the introduction of new CPU core configurations. 4+4 big.LITTLE designs are out, in favor of one or two behemoth cores followed by two or three slightly smaller big cores, and then the four usual energy-efficient cores. Leading this trend is the aforementioned competition for silicon area, but also the growth in powerhouse CPU cores.
You only have to compare the size of Samsung’s gargantuan M4 core to the Cortex-A75 paired alongside to see why Samsung opted for the 2+2+4 layout. Arm’s latest Cortex-A77 is a 17 percent larger core than the A76 and Samsung’s next-generation core might be larger still. Similarly, Apple continues to power its chip with large, powerful CPU cores. Larger cores help to push smartphone performance into low-end laptop territory and are also key to boosting gaming potential. However these big cores aren’t always equal, as we’ve seen with the Snapdragon 855 versus Exynos 9820, and we might see larger CPU performance divergences in the coming years.
Likewise, we’ve seen the shrink to 7nm benefit the power and area efficiency of flagship SoCs, and this will soon begin to benefit mid-tier chips too. However, as smartphones push for laptop-class performance, chip designers will need to carefully consider the area, performance, and power aspects of their CPU design. There’s also the question of whether we’ll see a divergence between phone and 2-in-1 Arm notebook chips in the coming year or so.
4 big + 4 small core designs will be reserved for laptops, with phones opting for three-tier solutions
Additionally, smartphones don’t need four super-powerful cores, especially as battery life is a chief concern. One or two cores for the heavy lifting, backed up by moderate and low-power cores for other tasks seems like a sensible design choice. 2+2+4 CPU cores for phones this generation are likely here to stay for 2020. Although, we may see 4+4 designs powered by the likes of the A77 destined for laptops and other applications that require high peak performance, and aren’t so constrained by battery capacity.
2020 chips in a nutshell
Chip announcements scheduled for later this year and appearing in 2020 devices share a few features in common. Flagship chips will be built on 7nm or 7nm+ FinFET processes, offering only marginal improvements to energy efficiency compared to the previous step down from 10nm. Smartphones will surpass previous CPU and GPU benchmark highs, while pushing 5G and machine learning capabilities into the mainstream.
However, the high-end chipset market is set for increasing diversity. Between custom CPU and GPU designs, in-house machine learning silicon, unique 5G chipsets, and a host of other features, the differences between an Exynos, Kirin, and Snapdragon chipset are set to grow larger still. Although not necessarily in terms of performance that consumers can really notice. Mid-tier chips will likely shape up similarly diverse and powerful. What remains to be seen is how aggressively priced chip designers can make 5G for mid-range consumers.