Samsung has released the Galaxy Note 7 with two different chipsets, depending on the market. The North American markets benefit from the Qualcomm Snapdragon 820 System-on-Chip and the rest of the world benefits from the Samsung Exynos 8890 System-on-Chip. We've already seen these two chipsets compared running a number of different benchmarks and the results show that the Qualcomm-powered model has an advantage in 3D benchmarking whereas the Samsung-powered model has an advantage in CPU benchmarking. Samsung explains that users will not be able to tell a difference between the two devices in day to day use: both are high end chipsets running with plenty of RAM (4 GB), identical memory controller and display units.
Before we take a look at the results, let's detail the Galaxy Note 7 and the two chipsets. Firstly, the Galaxy Note 7 is based around a QHD, 5.7-inch, SuperAMOLED display, 4GB of RAM and 64GB of storage. There's a MicroSD card slot, a 3,500 mAh rechargeable battery and a 12MP main camera. Of the two chipsets, firstly there's the Qualcomm Snapdragon 820. This is a 64-bit, big.LITTLE chip with two dual core, custom designed application processor clusters clocked at 1.6 GHz and 2.15 GHz for the lower and higher performance tier respectively. The Snapdragon contains the Adreno 530 GPU. The Samsung Exynos 8890 chipset is also a 64-bit, big.LITTLE design but has twice as many application cores: there's a quad core 2.3 GHz custom application processor based around Samsung's Mongoose design for the higher performance chip, and a quad core, 1.6 GHz ARM Cortex-A53 chipset for the higher efficiency cluster. The Exynos 8890 also includes ARM's Mali-T880 MP12, that is, the twelve core version of the Mali-T880 GPU.
By way of background to the thermal tests, this was something of a focus for 2015 mostly due to Qualcomm's Snapdragon 810 chipset, which runs hot. The reason for this is because the ARM Cortex-A57 application core is powerful but uses a lot of energy, and much of this is converted into heat. Although chipsets had been running warm inside smartphones and tablets for a number of years, in 2015 there was a very real problem of smartphones running noticeably slower than their advertised performance because of the amount of heat produced by the chipsets, causing clock speeds to be reduced to avoid damaging the chipset. Things are a lot better in 2016 thanks to more efficient chipset designs, but device performance still suffers through thermal throttling.
Firstly, for one run benchmarking, a number of CPU tests were run to compare the Snapdragon 820's custom Kryo design with the Samsung Exynos Mongoose core. The Qualcomm chipset is already at a numbers' disadvantage here: it has half the number of cores and the higher performance cores are clocked at a lower speed compared with the Samsung design, 2.15 GHz rather than 2.3 GHz. Assuming the chip architecture is the same - and it isn't - you would expect the Mongoose to score considerably higher in a multicore benchmark. You would also expect a small difference in single core benchmarking. The results show that the Exynos is, clock for clock, the better performance processor using the newly released Geekbench 4 but the difference is under 5%. For the multi-core benchmark, here things are closer than you might expect with the Samsung scoring around 141% of the Qualcomm chipset. Samsung are traditionally experts at multicore processors. Perhaps because the Snapdragon 820 uses four Kryo cores where the Exynos blends Samsung's custom design with ARM's reference Cortex-A53, we see the Qualcomm punch above its weight? However, whilst both chipsets are powerful, the Exynos has an advantage here.
What happens when you run multiple tests, however? A number of tests were run using the Geekbench 3 benchmark (rather than Geekbench 4, because the third generation has fewer delays to allow the chipset to cool down). Here, both chipsets showed some effects of thermal degradation. For the Exynos chipset, the single core benchmark figure showed a small drop from a little over 2,100 to a little under 2,100. The Snapdragon showed a steeper drop from around 22,50 to a little over 2,100. For multicore benchmarking, here we see an oddity with the Snapdragon 820: the score starts at 5,000 but rises to almost 5,300 and drops to under 4,500 during the eleven runs, but ends at effectively the same level at the starting point. The Exynos' multicore benchmark also shows some volatility, but appears to drop from close to 6,400 to around 6,000 over the same period. Temperature-wise, the Exynos 8890 increased from 30 degrees to almost 35 degrees over eleven tests whereas the Snapdragon moved from 29 degrees to over 37 degrees. Unfortunately, the data is inconclusive but it appears to show that the Exynos is more sensitive to changes in temperature compared with the Snapdragon, and takes longer to heat up.
Let's take a look at the GPU tests, where the Snapdragon 820's reputation precedes it: Peak 3DMark scores brush 2,500 in the Slingshot ES 3.1 benchmark, whereas the Exynos manages to exceed 2,100. A number of tests were run using this benchmark to measure peak and sustained performance, with the Snapdragon 820 outperforming the Exynos 8890's first run graphical benchmark, but it also retained this advantage over a number of runs but maintained a similar temperature. Indeed, the Snapdragon's test results were between 2,000 to 2,500 and the Exynos scored from 1,350 to 2,125. However, in some longer term tests such as the GFXBench, the Snapdragon 820's performance over the Exynos 8890 was reduced or nullified. For gaming, such as GTA: San Andreas and especially Dead Trigger 2, the Exynos 8890-powered Galaxy Note 7 was noticeably less smooth than the Snapdragon 820 when handling the more complicated scenes after twenty minutes of gameplay.
The conclusions of these tests mirrors the other benchmarks that have compared the Snapdragon 820 and the Exynos 8890. Qualcomm's silicon has a CPU deficit compared with the Samsung, both in terms of outright performance and in efficiency, as measured by temperatures. The Adreno 530 GPU is more capable than the ARM Mali-T880 in terms of outright performance. For day to day use, the CPU is used more than the GPU, so the numbers would give the Samsung Exynos 8890 a small advantage. However, both chipsets should perform strongly unless hindered by the operating system or Samsung's user interface - not forgetting that synthetic benchmarks are not a true reflection of real world performance. It remains to be seen if a benchmark advantage is noticeable in customer hands.