Since the explosion of Android tablets started almost 10 years ago several CPU (central processor unit) manufacturers have come and gone. In the beginning high profit and high volume drew companies into the space, but as the volume of Wi-Fi Android tablets dropped and competition grew a few clear leaders have emerged. Those leaders include Rockchip, Mediatek (which also makes CPUs for telecom tablets and smartphones), and Allwinner Tech. These companies all make chips based on the ARM architecture, so many of their chips compete head to head and are fairly similar in spec and performance.
To keep it simple this article will focus on Rockchip since Hatch routinely uses their CPUs. The main reason we use more Rockchip is due to flexible customizations (important when making custom Android devices), engineering support, and because we have stronger relationships with Rockchip engineers. The other companies also make high quality Android CPUs that work for custom projects and we are supportive of using them if our customer requests.
The list below provides information about the leading Rockchip CPUs that are recommended for use in custom Android Wi-Fi devices in order of performance, from high to low end.
The RK3399Pro is called a ‘server level’ CPU. It’s mainly intended for use in applications that demand high performance such as an Edge AI server, industrial applications, client-side facial recognition, and others of this nature.
The CPU contains 6 (hexa) ARM cores, consisting of 2 Cortex-A72 (1.8GHz) and 4 Cortex-A53 (1.5GHz), a NEON coprocessor, Mali T864 GPU, and an NPU. It can run multiple learning platforms such as Caffe and Tensor Flow. The RK3399Pro supports multiple display outputs up to 4k resolution and multiple camera inputs up to 13MP. It also has native support for USB type-C protocol.
(Before the RK3399Pro came the RK3399. The RK3399Pro is the RK3399 with the integration of the RK1808 IC. The RK1808 provides the NPU (neural network processor unit) mentioned above.)
The RK3288 is a high end Android CPU that features excellent display support and strong processing power. This chip is used in a range of consumer, business, and industrial devices. Many large screen advertising displays use this chip. Applications include live video streaming with add-on electronics (like temperature sensor), laptops, and access control terminals. The CPU contains 4 (quad) ARM Cortex-A17 cores that deliver speed up to 1.8GHz and a Mali T764 GPU. It supports up to 4k display resolution, dual display output, and dual camera up to 13MP (with internal ISP).
The RK3368 is similar to the RK3288 with slightly lower specs. It still offers excellent multimedia features and does a great job in high level consumer or business applications. The RK3368 is commonly used for educational tablets, TV boxes, advertising displays, and premium tablets.
This CPU has an 8 (octacore) architecture with 8 Cortex-A53 cores that run up to 1.5GHz. It supports up to 4k video HDMI output powered by a PowerVR G6110 GPU. The internal ISP supports 1080p recording and up to 8MP images.
The RK3326 is a mid-range CPU that has become popular with devices like retail tablets and smart speakers that have moderate performance requirements and need the newest technologies. The chip is a step up from the RK3128 in that it provides faster processing speed and an internal ISP for image processing.
This CPU has a 4 (quad) core Cortex-A35 processor that runs up to 1.5GHz. The Mali-G31MP2 GPU delivers video output up to 1080p resolution. The internal ISP supports video up to 1080p resolution and images up to 8MP.
The RK3128 is the entry level CPU intended for mass market consumer level devices. Its high volume ensures stable functionality and reliable performance in tablets and TV boxes for lower resolution displays. It’s a solid option for custom Android devices that need long battery life with limited functionality.
This CPU has 4 (quad) Cortex-A7 cores running up to 1.2GHz. It integrates a Mali-400MP2 GPU that provides video output up to 1080p resolution. The CPU also supports cameras with recording up to 1080p and images up to 5MP.
Some CPUs have multiple versions that offer slightly different features. For example, the RK3128 and RK3126c are exactly the same CPU, but only the RK3128 has HDMI connectivity and supports DDR2. For products that don’t leverage the full features of a CPU using the ‘cost down’ version (like the RK3126c) saves cost on the BOM (bill of materials). Once the requirements of a product are clearly defined with a client Hatch will help to accurately identify the most suitable chip to use.
When architecting custom Android hardware the first thing to consider is which CPU to use. A CPU is the central IC chip that powers a digital product, sometimes referred to as the ‘brains’ of a product. Choosing the CPU is the most fundamental design decision for your product because the capabilities and limitations of this IC predicate the capabilities of the entire device.
Two CPU companies that continue to dominate homegrown China products are Mediatek (Taiwan) and Spreadtrum (China). While Qualcomm, globally, is the leading brand for top tier mobile phone CPUs, it’s more suitable for high volume (100k+ units) consumer devices than lower volume (10k+) custom devices. Designing phones with Qualcomm CPUs requires more engineering expertise so development costs are higher. The performance benefits that Qualcomm CPUs provide are often overkill for what custom device customers need anyway.
Mediatek and Spreadtrum advertise many different CPUs on their websites. The reality is that only a few of them are commonly used by players in Shenzhen’s manufacturing ecosystem, the world’s source for tech hardware. The websites show several older and brand new CPUs, neither of which are good for custom products. Older CPUs may soon become obsolete and lack performance. Brand new CPUs are often too new for stable mass production and their features are overkill for the needs of most custom projects. The CPUs that have become popular gained traction because they offer the best value for the segment they serve.
(Relatively) High End Segment 4G
Both Mediatek and Spreadtrum are showing 5G chips on their website and a few large (mostly Chinese) mobile phone brands have already released phones using CPUs from Mediatek’s 5G Dimensity line. When new chips come out larger brands which reliably sell high volumes are the first to market with products. It takes a lot of engineering resources to develop a product using a new chip which is why CPU manufacturers partner with high volume brands to release the initial products. Once these brands have come out with products and the system becomes more stable Shenzhen’s smaller development companies start releasing products for smaller brands.
Because 5G solutions aren’t stable enough for smaller market brands yet they’re still not ready for most custom projects. At this point 4G CPUs are still the most practical for custom projects as the engineers are most comfortable making products on these platforms. Therefore, even for the high end segment, this article focuses on 4G CPU options.
This is Mediatek’s top of the line 4G CPU. It offers high performance for playing resource intensive video games and high end camera support. Mediatek describes it like this:
“An upgraded octa-core CPU boosts speeds up to 2.05GHz. Using a mix of the latest Arm Cortex-A76 and Cortex-A55 in combination with a large L3 cache, the G90 series increases multi-threaded performance up to 9%1 beyond direct competitors.
With speeds up to 800MHz, the latest Arm Mali-G76 3EEMC4 GPU can play Fortnite and PUBG incredibly smoothly, blazing through Manhattan benchmark up to 26%1 faster versus direct competitors.
Up to 10GB of LPDDR4x at 2133MHz1 (4266MHz1 effective) provides generous bandwidth and memory capacity, while the latest UFS 2.1 storage yields ultra-fast data-streaming.”
The P70 replaces the successful P60 offering up to 13% faster performance and 35% lower power consumption. The chip includes an upgraded dedicated AI Processor Unit (APU) that provides up to 30% more processing efficiency than its predecessor. This chip is marketed towards gamers, camera enthusiasts, and advanced AI applications. Could be a good choice for custom products that need high performance onboard processing. Here’s what Mediatek has to say:
“The MediaTek Helio P70 incorporates a powerful Arm Cortex-A73/A53 octa-core CPU complex with an impressive Arm Mali-G72 class GPU. Versus the prior P60, the faster clock speeds generate up to 13% more performance. In-hand, there’s support for 20:9 displays at Full HD+ resolution that allow users to enjoy the most beautiful and modern smartphone designs with full fascia coverage.
MediaTek’s exclusive CorePilot 4.0 technology manages how tasks are assigned between processing resources, with a power management focus that’s on maintaining a sustainable, fast user experience through thermal management, UX monitoring and Energy Aware Scheduling (EAS+).”
This chip offers similar, but slightly reduced, features as the P70. It became mainstream in early 2020, about a year after the P70. Mediatek has this to say:
“The G70 incorporates a pair of powerful Arm Cortex-A75 CPUs operating up to 2GHz, plus six Cortex-A55 CPUs in a single, octa-core cluster. These are interlinked and share a large L3 cache for improved performance plus up to 8GB of fast LPDDR4X memory. For gaming, an efficient, high-performance Arm Mali-G52 class graphics processor operates up to a speedy 820MHz.
A multitude of hardware accelerators, such as a dedicated depth engine, Camera Control Unit (CCU), Electronic Image Stabilization (EIS) and Rolling Shutter Compensation (RSC) technology enhances video panning and ultra-fast recording (up to 240fps).
Ideal for popular AI-camera tasks such as object recognition (Google Lens), Smart Photo Album, scene detection and segmentation with background removal, and Bokeh-shot enhancements.
With MediaTek NeuroPilot support and full compliance with Android Neural Networks API (Android NNAPI), developers and device makers have the best possible ecosystem for Android enhancements and app development, with support for many common AI frameworks.”
Upper Mid Range 4G
These lower cost CPUs provide terrific performance for many dedicated single app custom Android products. The CPUs in this category provide an excellent balance of performance and features.
Mediatek P35 (MT6765) and P22 (MT6762)
These chips appear to use the same core, with key differences in display and camera resolution. The P35 supports display resolution up to 2400×1080, dual 13+13MP cameras, and a single 25MP camera. The P22 provides respectable, yet reduced, display resolution up to 1600×720, dual 13+8MP cameras, and a single 21MP camera. Both chips come with a suite of Mediatek technologies like CorePilot, Imagiq, MiraVision, NeuroPilot, Pump Express, Tiny Sensor Hub.
Mid Range 4G
Mediatek A22 (MT6761)
The A22 has the same feature set as the P22, except it uses a quad core architecture while the P22 uses an octa core architecture. The A22 is a good choice for custom Android devices that need a solid feature set, but don’t demand excessive computing power. Noteworthy for possible IoT applications “its tiny, ultra-low power sensor hub is ideal for apps that require always-on sensor readings (pedometers or vocal-triggers), without having to engage the main CPU complex, providing significant power savings”, according to Mediatek.
Spreadtrum trails behind Mediatek in technology, market prestige, and number of CPU models, but the limited options it offers do a good job covering the low to mid-range price driven market. The 9863A delivers a strong octa core architecture, with speeds up to 1.6GHz. The camera resolution tops off at 16MP and supports dual cameras. Screen resolution supports up to FHD+ (2160*1080).
The 6739 has dominated the market for high quality lower-mid spec consumer devices since 2017 (and probably for the foreseeable future). This means a very high volume of these chips have shipped out, making the electronics and firmware stable, exactly what many custom products need most. Facing competition from Spreadtrum’s 9863 on the high end and Spreadtrum’s 9832 on the low end, a quality reputation continues to drive sales, even at a higher price point. Here’s what Mediatek wants you to know:
“Combined within the MT6739 is a highly efficient 64-bit quad core, ARM Cortex-A53 CPU that operates up to a fast 1.5GHz. Its IMG GE8100 GPU operates up to 570MHz and supports the latest 18:9 display type with HD+ (1440 x 720) resolution.”
For the most price driven full feature smartphone market the SC9832E delivers. Supporting cameras with a resolution up to 13MP, including 1080P video recording, and display resolution of HD+ (1440×720) or under, the SC9832E has had dominating success with entry level smartphones in price sensitive markets. As the chip has been used for years by both regional brands as well as tier 1 international brands its capabilities have been proven in the consumer market.
Low End Range 3G
Mediatek 6580 and Spreadtrum 7731
Both of these chips have had very long and successful lives, making them the headlining 3G chipsets for their respective brands over the past 6+ years. The specs of these two chips are fairly similar. Both have a quad core Arm-A7 architecture, support up to 1440×720 screens, and a 13mp (6580) or 8mp (7731) camera. There are few reasons to use either of these chipsets anymore, but a small market still exists. Custom Android hardware that doesn’t need high specs or high bandwidth may be a good match. These chips are probably still produced to serve legacy products more so than used to develop new ones.
An Alternative Approach
In situations where a brand wants to use a Qualcomm CPU there are now Qualcomm SOM (system on module) options available. Using an SOM allows for faster and more economical development of custom Android hardware using a Qualcomm platform. End products using SOMs are usually higher cost and, depending on the product, require a thicker case, but come with some advantages also.
A SOM is a module that contains a complete mobile phone PCBA in a miniature form factor. Some SOMs come pre-certified for different international safety and mobile network standards. This makes getting those certifications for the final product less expensive and faster. Products can be designed using an SOM by soldering the SOM on a ‘main’ PCB and then adding peripheral electronics to the main PCB. Peripheral electronics include ports, such as USB-C, ethernet, HDMI, etc, special electronics such as NFC, LoRa, etc, and interfaces with a screen, battery, touch panel, etc. If using Mediatek or Spreadtrum CPUs the IC chips are soldered directly on the main board.
There you have it, party people; a bunch of chips worth getting to know for your next custom Android project. Think about what works for you or give us a shout at Hatch, and we’ll help you decide.