Cortex-A72 is an evolution on Cortex-A57, which was ARM’s previous high-end ARMv8-A CPU core design. Announced way back in early 2015, the A72 is stated by ARM to be around 15-30% faster than the A57 on a clock for clock basis, with improved power efficiency. Interestingly, Qualcomm uses the A72 in their Snapdragon 650 series designs, so I’m not expecting it to be as fast as the company’s custom Kryo cores used in the Snapdragon 820. In the Kirin 955 specifically, we’re seeing a big.LITTLE combination of four Cortex-A72 cores and four Cortex-A53 cores, with clock speeds set at 2.5 GHz and 1.8 GHz respectively. This is a typical design that sees the A72 cores used for high performance workloads, while the A53s are included for energy efficiency. The only major change compared to HiSilcon’s previous flagship SoC, the Kirin 950, is a 200 MHz clock speed increase for the A72 cores.
On the GPU side we’re seeing an ARM Mali-T880 MP4 clocked at 900 MHz. This is the same GPU that is used in Samsung’s flagship Exynos 8890 used in some variants of the Galaxy S7 and S7 Edge, although Samsung opted for a 12-core design to better support 1440p displays. The Kirin 955 uses just a four-core configuration, but its 250 MHz higher clock speed should offset some of the performance loss from using fewer compute cores. On the memory side, there’s a 64-bit dual-channel LPDDR3/ LPDDR4 hybrid controller that provides 25.6 GB/s of bandwidth. The model of P9 that you buy determines what amount of RAM and RAM technology that you’ll receive. Devices with 32 GB of storage get 3 GB of LPDDR3 memory, while 64 GB models get 4 GB of LPDDR4 memory. The Kirin 955 includes an integrated Balong modem that supports up to Category 6 LTE. The single-SIM variant of the P9 in particular supports a ton of LTE bands (18 to be exact, covering the vast majority of networks worldwide), plus seven 3G HSPA bands. The dual-SIM models cover a slightly different array of bands, but support is still good across the board.
As for other connectivity, nothing is out of the ordinary: Wi-Fi 802.11a/b/g/n/ac on 2.4 and 5.0 GHz, Bluetooth 4.2, NFC, DLNA and GPS+GLONASS. Oddly, dual-SIM models don’t have NFC support. As with most high-end phones, the Huawei P9 is fast to use. I did notice that, on occasion, apps decided to reload rather than resume when I switched to them after short periods - and I have a model with 3 GB of RAM in to review - but I suspect this is due to aggressive software management of memory resources. Aside from this, I experienced no issues with the P9’s performance in general use. But how does the Kirin 955 compare to the Snapdragon 820? Let’s take a look at some benchmarks.
The Kirin 955’s CPU performance is reasonably impressive, and stacks up well against the Snapdragon 810. The Huawei P9 was nine percent faster on average in CPU-limited workloads than the HTC 10 and LG G5; both are Snapdragon 820 devices. The biggest performance disadvantage came in Chrome while running web-based benchmarks, where the Kirin 955 was universally slower than the Snapdragon 820. I suspect this has to do with software optimization focusing on the more common Qualcomm chips. The P9 also held a 14% CPU performance advantage over the Exynos 8890 in some models of the Galaxy S7 Edge. Against the iPhone 6s we’re seeing almost equal performance. We’re also seeing much better performance than last-gen SoCs like the Snapdragon 810 (around 50% better than the Nexus 6P), Snapdragon 808 (69% faster than the Nexus 5X), and Exynos 7420 (21% faster than the Galaxy S6).
