We have known about the MediaTek Helio X20 for some months now thanks to a number of leaks and documentation detailing the new 64-bit System-on-Chip and it's three tier - called the Tri-Cluster by MediaTek - structure, which consists of an advertised ten processor cores. There is also an eleventh, which I will write about later in the article. MediaTek's approach is designed to both improve performance and reduce power consumption across the board, depending on what the device is being tasked at the time. MediaTek's press release cites that the X20 can use up to 30% less power compared with dual clusters thanks to the innovative processor structure. The Helio X20 also includes a built-in Category 6 LTE modem, which includes carrier aggregation.
In the details, the Helio X20 consists of three clusters of application processor cores and each is designed with a particular workload in mind. There is a quad core cluster of ARM Cortex-A53 cores clocked at up to 1.4 GHz, designed for light processor workloads. The next tier consists of another quad core of ARM Cortex-A53s, here clocked at up to 2.0 GHz. The most powerful cluster consists of a dual core ARM Cortex-A72 application processor with a maximum clock speed of up to 2.5 GHz, which is designed for the highest workload (in MediaTek's terms, "extreme performance"). These clusters work in a similar way to a transmission in a car, in that depending on the workload (or road speed) the processor will use a different set of application cores. For light duties, the lease powerful Cortex-A53 cores will be used: the Cortex-A72 cores could be used, but these are less efficient and would use more power for the workload. MediaTek use an upgraded version of their CorePilot processor management and scheduling algorithm to control what application processor cores and clusters are used depending on the workload. The technology represents an extension of the reference big.LITTLE technology used by a large number of System-on-Chips, whereby a lower powered cluster of cores is joined by a higher powered cluster of cores.
Much like Qualcomm, MediaTek is including "added extras" into its System-on-Chips. For the Helio X20, these include support for dual main cameras and the processor includes a built-in 3D-depth engine that reduces the time it takes to take photographs. The display driver can run at 120 Hz, twice the current 60 Hz refresh rate, in order to improve how fluid and responsive the device feels to use when viewing web pages or movement-laden video. The Helio X20 also include the ARM Cortex-M4, the eleventh core. This is a special low power processor core designed with certain background tasks in mind such as MP3 playback, voice activation and operating sensors. As such, depending on the workload, it can act as a fourth tier - when the device is locked and otherwise doing nothing apart from playing music, it could be relying on the Cortex-M4 core rather than the 1.4 GHz Cortex-A53 cores.
MediaTek are planning on making the Helio X20 available in sampling quantities in the next couple of months and are expecting the first devices to ship with the new chipset before the New Year. We will need to wait until we have these first consumer devices before we can measure how effective the Tri-Cluster technology is in the real world (and away from synthetic benchmarks) for device performance, heat, smoothness and of course battery life. It is going to be an exciting time.