The Snapdragon 888 vs The Exynos 2100: Cortex-X1 & 5nm - Who Does It Better?

The new Galaxy S21 series of devices have been out commercially for a week now, and we’ve managed to get our hands on two Galaxy S21 Ultras – one with Qualcomm’s new Snapdragon 888 SoC, and one with Samsung’s new Exynos 2100 SoC. Both chipsets this year are more similar than ever, both now sporting similar CPU configurations, and both being produced on a new Samsung 5nm (5LPE) process node.

Ahead of our full device review of the Galaxy S21 Ultra (and the smaller Galaxy S21), today we’re focusing on the first test results of the new generation of SoCs, putting them through their paces, and pitting them against each other in the new 2021 competitive landscape.

The Snapdragon 888

• Qualcomm Details The Snapdragon 888:
  3rd Gen 5G & Cortex-X1 on 5nm

Starting off with the new Snapdragon 888 SoC, Qualcomm’s new flagship model makes iterative steps this generation, with the biggest changes of the new design actually being in the form of the new Hexagon 780 accelerator, which fuses together traditional scalar and vector DSP operations with tensor execution engines within one single IP block.

Of course, we’re also seeing upgrades elsewhere in the architecture, with the Snapdragon 888 being among the first SoCs to use Arm’s new Cortex-X1 CPU IP, promising large performance gains relative to last generation Cortex-A77 cores. The single X1 cores in the Snapdragon 888 clocks in at 2.84GHz – the same as the previous generation Snapdragon 865’s prime Cortex-A77 cores, and less than the 3.1GHz and 3.2GHz Snapdragon 865+ and recently announced Snapdragon 870 SoCs.

Alongside the X1, we find three Cortex-A78 cores at 2.42GHz, again the same clocks as the previous generation 865 SoCs, but this time around with double the L2 caches at 512KB.

The Cortex-A55 little cores remain identical this generation, clocking in at 1.8GHz.

Although we had been expecting 8MB L3 cache flagship SoCs this year, it does look like Qualcomm opted to remain at 4MB for this generation – but at least the company dons the X1 core with the maximum 1MB L2 cache configuration.

On the GPU side of things, Qualcomm’s new Adreno 660 GPU now clocks in up to a peak 840MHz – a whopping 43% higher frequency than the Snapdragon 865 GPU. The company’s performance claims here are also astonishing, promising a +35% boost in performance. We’ll have to see how this all ends up in terms of power consumption and long-term performance in the later dedicated GPU section.

What’s quite different for the Snapdragon 888 this year is that Qualcomm has moved from a TSMC N7P process node to Samsung’s new 5LPE node – the generally wildcard in this whole situation as we haven’t had any prior experience with this new 5nm node.

The Exynos 2100

• Samsung Announces Exynos 2100 SoC:
  A New Restart on 5nm with X1 Cores

On the Samsung LSI side of things, we find the brand-new Exynos 2100. Unlike the Snapdragon 888’s more incremental changes in terms of SoC design, the new Exynos is a rather large departure for Samsung’s SoC division as this is the first flagship design in many years that no longer uses Samsung’s own in-house CPU microarchitecture, but rather reverts back to using Arm Cortex cores, which in this case is also the new Cortex-X1 and Cortex-A78 cores.

From a high-level, the CPU configuration of the Exynos 2100 looks nigh identical to that of the Snapdragon 888, as both are 1+3+4 designs with X1, A78 and A55 cores. The differences are in the details:

The X1 cores on the Exynos 2100 clock slightly higher at up to 2.91GHz, while the Cortex-A78 clock in significantly higher than the Snapdragon as they reach 2.81GHz. The Cortex-A55 cores are also quite aggressive in terms of frequency as they now reach 2.20GHz – so overall across the board higher clocks than the Snapdragon variant.

Where the Exynos isn’t as aggressive though is in its cache configurations. Most importantly, the X1 cores here only feature 512KB of L2 cache, which is a bit weird given the all-out-performance philosophy of the new CPU. The Cortex-A78s also see the usage of 512KB L2 caches, while the little A55 cores feature 64KB L2’s – less than the Snapdragon counterparts.

Much like the Snapdragon, the L3 cache also falls in at 4MB rather than the 8MB we would have hoped for this generation, however Samsung does surprise us with the usage of an estimated 6-8MB system level cache, up from the 2MB design in the Exynos 990.

On the GPU side of things, we see a Mali-G78MP14 at up to 854MHz. That’s 27% more cores and 6.7% higher frequency, and the company is also boasting massive performance gains as it touts a 40% generational improvement.

Let them fight

In today piece, we’ll be mostly focusing around CPU and GPU performance, as an especially interesting comparison will be to see how the two designs do against each other, given that they both now use Arm’s newest Cortex-X1 cores and both are sporting the same manufacturing node.

The GPU comparisons will also be interesting – and maybe quite controversial, as the results won’t be what many people will have been expecting.

While we would have liked to showcase AI performance of the two SoCs – unfortunately the software situation on the Galaxy S21’s right now means that neither SoC are fully taking advantage of their new accelerators, so that’s a topic to revisit in a few months’ time once the proper frameworks have been updated by Samsung.

Table Of Contents

• The Snapdragon 888 & Exynos 2100
• 5nm / 5LPE: What Do We Know?
• Memory Subsystem & Latency: Quite Different
• SPEC - Single Threaded Performance & Power
• Mixed-Usage Power & Preliminary Battery Life
• GPU Performance & Power: Very, Very Hot
• Conclusion & End Remarks