MediaTek Helio X27 MT6797X vs Qualcomm Snapdragon 625 vs Qualcomm Snapdragon 615 MSM8939

MediaTek Helio X27 MT6797X

The Mediatek Helio X27 MT6797X is an upper mainstream ARM SoC for smartphones (mainly Android based). It is manufactured in a 20 nm process and is equipped with 10 CPU cores. Two fast Cortex-A72 cores are running at up to 2.6 GHz (performance), four Cortex-A53 cores at up to 2 GHz (balanced) and four Cortex-A53 cores at up to 1.6 GHz (efficiency). All cores support 64-bit and the utilization of three clusters is supposed to improve efficiency according to Mediatek. The two A72 cores are only designed for short "Burst-Performance scenarios" according to Mediatek and are probably not used for sustained workloads. Compared to the similar named MT6797, the MT6797X was introduced later and offers higher clock speeds for CPU and GPU.

The integrated ARM Mali T880 MP4 (according to Wikipedia) GPU is clocked at up to 875 MHz and has four cluster (from 16) from the Midgard (4th Gen) architecture.

The chip also includes an LTE modem (Cat. 6 300/50 Mbps, DC-HSPA+, TD-SCDMA, EDGE, CDMA2000, ...) as well as a WLAN 802.11ac (280 Mbps) modem. GPS/Glonass/BeiDou is supported for location. The integrated video encoder can handle up to 4Kx2K H.265 at 30 fps and HDR. The SoC can also decode H.265, H.264 and VP9 in 4K30. 

Power Consumption

The processor is manufactured in a 20 nm process at TSMC and should have an average power consumption under load.

Qualcomm Snapdragon 625

The Qualcomm Snapdragon 625 (SD625) is a mid-range octa-core SoC with eight ARM Cortex-A53 cpu cores at up to 2 GHz, an Adreno 506 GPU, a DDR3L-1866 memory controller and a X9 LTE (Cat 7, 4G+, 300 Mbps down, 150 Mbps up) modem. Furthermore, the chip supports 802.11ac WiFi and Bluetooth 4.1. It is manufactured in 14nm FinFet. The processor performance should be similar to a HiSilicon Kirin 650, which also offers 8 Cortex A53 cores at up to 2 GHz. However, due to the modern manufacturing process, power consumption and throttling should be better with the Snapdragon 625.

Qualcomm Snapdragon 615 MSM8939

The Qualcomm Snapdragon 615 MSM8939 is a mid-range ARMv8-based SoC largely for Android tablets and smartphones. Announced in February 2014, the S615 is one of the first 64-bit capable SoCs from Qualcomm. In addition to 8 Cortex-A53 CPU cores at up to 1.7 GHz, the SoC integrates an Adreno 405 GPU with a 2x 32-bit memory controller (LPDDR3-1600, 12.8 GB/s) and supports Wi-Fi (802.11ac), Bluetooth 4.0, UMTS, and LTE.

CPU

The Cortex-A53 is the successor to the very popular Cortex-A7 design. In addition to the new 64-bit capable ARMv8 ISA, the cores offer a variety of other improvements such as better branch prediction. This leads to a significantly higher performance per clock, which is even above the older Cortex-A9.

The eight cores of the Snapdragon 615 are divided into two quad-core clusters, each optimized for a different operating point. While one cluster can clock up to 1.7 GHz to handle more demanding applications, the other cluster is limited to a maximum of 1.0 GHz for energy-saving purposes. All eight cores can be active at the same time, although most applications aren't parallelized to support 8 cores efficiently.

Overall, the Snapdragon 615 offers a performance similar to that of the older Snapdragon 600 (Krait architecture).

GPU

Another new feature is the integrated graphics unit named Adreno 405 (550 MHz). The Adreno 400 series has been substantially redesigned and supports DirectX 11.2 (FL 11_1) including hardware tessellation, OpenGL ES 3.1, and OpenCL 1.2. Furthermore, the performance has been significantly improved, which is now similar to the Adreno 320 and PowerVR G6200.

Features

The Snapdragon 615 offers numerous wireless technologies such as Bluetooth 4.0 and WLAN 802.11a/b/g/n/ac as well as a Multi-SIM cellular modem supporting LTE cat. 4 (up to 150 Mbps), WCDMA, CDMA, EV-DO, TD-SCDMA and GSM/EDGE.

The SoC can encode and decode 1080p videos using dedicated hardware and stream content to displays with up to 2560 x 2048 pixels. A large number of video codecs including H.265 (playback only) will be supported. The camera ISP can handle sensors with up to 21 MP.

Power Consumption

The Snapdragon 615 is manufactured by TSMC in a 28 nm LP process. According to the specifications, we expect a medium or medium-high power consumption for use in medium-sized or larger smartphones and tablets.