Qualcomm is the leading supplier of wearable chipsets for smartwatches. The company’s last smartwatch chipset, the Snapdragon 3100, introduced an optional ultra-low power processor, but didn’t make significant improvements to performance over the previous generation. I believe that this may have hurt the non-Apple wearable market, but the overall wearable market has continued to grow. Performance was a problem with the initial Snapdragon Wear 1100 and 1200, and while the 2100, 2500 and 3100 seemed to address this to a degree, I think many were left wanting more. As a daily Apple Watch wearer, I have not been pleased with Google’s Wear OS performance on the latest Snapdragon chipset. Hopefully all that changes with the Snapdragon Wear 4100 and 4100+ chipsets Qualcomm announced earlier this week.
The new Snapdragon 4100 and 4100+ are effectively the same SoC, save the fact that the 4100+ features the Always-On Ultra-Low Power dedicated chip on top of the 4100 SoC. The Snapdragon 4100 SoC itself was built using the 12nm process node—a significant reduction from the last generation’s 28nm process node. Shrinking the process node gave Qualcomm more die space to integrate bigger and faster cores, increasing the chipset’s performance. Let’s take a closer look at the new offerings. Since the Snapdragon 4100+ is just the Snapdragon 4100 with the Always-On ultra-low power companion chip, I will simply refer to the platform as the Snapdragon Wear 4100/+ from here on out.
Increased CPU and DSP performance
One of the fundamental problems with the original Snapdragon Wear platform was that it was saddled with a much lower performance ARM Cortex-A7 processor. Originally launched in 2013, this processor has been outdated for years and is barely in use anywhere anymore. It was time for Qualcomm to sunset the chip in favor of something more modern: a 64-bit compatible, quad core Arm Cortex-A53 CPU configuration. Ironically, the Cortex-A53 is an even older ARM CPU architecture than the A7, but it is much more powerful and exists in an entirely different class of performance. Qualcomm claims a 85% performance improvement over the previous generation, when comparing the 1.7 GHz clock speed of the A53 cores to the 1.1 GHz clock speed of the old A7 cores. While I would’ve liked to see the even faster, more efficient A55 core instead, it was likely cost prohibitive. Qualcomm also doubled the DSPs in the Snapdragon 4100/+, from one QDSP v56 and a modem DSP, to two of the same QDSP v56, a dedicated DSP for modem and GPS, and another dedicated DSP for sensors.
Memory performance scaling
The memory on this new SoC is a 10x10 ePoP but also supports 4x4 and 8x8 configurations (as did the Snapdragon Wear 3100). It’s worth noting that the new memory configuration will be LPDDR3 @ 750 MHz, which is much faster than the Snapdragon Wear 3100’s 400 MHz DDR3, and another 85% increase in performance according to Qualcomm. While Qualcomm did not upgrade the memory from LPDDR3 to LPDDR4, which is inherently faster and lower power, this may have been due to cost concerns and ePOP technology availability. That said, moving forward it is important for Qualcomm to balance CPU performance improvements with memory bandwidth improvements in order to ensure that the memory does not become a bottleneck for the CPU.
Graphics and camera performance
The graphics and camera performance is where Qualcomm really upped its game on the new Snapdragon Wear 4100/+. The GPU went from an Adreno 304 GPU at 200 MHz to an Adreno 504 GPU at 320 MHz. Qualcomm has made many leaps and bounds in GPU architecture from the 300 series to the 500 series. As a result, although the clock speed is not anywhere near double, Qualcomm claims 2.5x faster GPU performance than the previous generation. This is a welcome improvement for a multitude of reasons. Having a faster GPU translates to richer, more detailed smartwatch graphics. Additionally, it enables the chipset to perform those tasks at lower power, which is key on such a power-constrained platform as a smartwatch. As a result, the chipset’s supported display resolution has increased to 1920x1080 at 30 fps (up from the previous generation’s 640x480 at 60fps). That said, I believe that somewhere between those two resolutions is where most smartwatch manufacturers will eventually land, since you do not need that many pixels on such a small screen. Qualcomm also upgraded the camera capabilities, doubling the amount of ISPs to support up to a 16 MP camera sensor (especially attractive for manufacturers of elder and kid watches which are continually growing segments of the smartwatch market.
What has not changed (much)
The Snapdragon Wear 4100/+ features the same Snapdragon X5 LTE modem as the previous generation, though it does come with new RFFE components (including new GaAs power amplifiers). The Ultra-Low-Power co-processor in the Snapdragon 4100/+ is only a slight upgrade from the Snapdragon 3100’s co-processor, which means that the long-term battery life of the next generation of smartwatches won’t improve much over the last generation. It will, however, support improved colors and richer screen-off experiences. All of that said, I do believe that the improvements to the Snapdragon Wear 4100’s main SoC will deliver battery life improvements to daily usage, possibly extending battery life to 2-3 days (up from 1-2 days on most smartwatches today). The Snapdragon Wear 4100/+ also comes with support for Bluetooth 4.2, as it did with the 3100, but adds support for 5.0 as well. I believe this is a major upgrade that should not be overlooked—Bluetooth 5.0 improves performance, range, security and battery life. I believe it should be the standard for all smartwatches in 2020, even though 4.2 is still an option.
In terms of performance, the Snapdragon Wear 4100/+ appears to be a major (and welcome) improvement on Qualcomm’s Snapdragon Wear line of processors. I believe that this platform will inspire a completely new era of Android and Wear OS watches, from a multitude of OEMs spanning fashion brands to smartphone OEMs. The most beneficial improvements, from a consumer standpoint, appear to be the chipset’s lengthier, fully-featured battery life, a fully-featured OS at higher resolutions and improved connectivity and range. The improvements to overall performance should also enable watch OEMs to deliver much snappier Android or Wear OS smartwatches, which will hopefully match smartphone-tier Google Assistant performance. Qualcomm had already been shipping the new SoC to OEMs, so look for watches featuring the Snapdragon Wear 4100/+ to launch within the next month or so.