« 7 reasons to buy Samsung Galaxy S7 and S7 edge
Top iOS apps and games of the week #10 »

Smartphone processors 101: simplifying the jargon

|March 11 2016 |Mobile Processors, Qualcomm

"The basics of what you need to know about mobile processors"

With every smartphone that has launched since about 2010, a few facts got thrown around quite a lot. There’s sensor X in the camera. There’s display technology Y in the phone. And, perhaps the most relevant, there’s processor Z under the hood.

With the advent of smart mobile devices, processors are upping the game for themselves, and this trend has led to the evolution of processors into multiple variants and models. Sometimes it is overwhelming for a consumer to effectively understand the difference between different processors in phones offered at a similar price point. Case in point being the differences between the LeEco Le 1s and the Xiaomi Redmi Note 3.

That’s where we try to come in. In this article, we’ll break down all the bells and whistles constituting the world of SoCs and processors, and will try to clearly distinguish between various types of processors out there.

What’s an SoC?

Within a phone, effective usage of space has paramount importance, and therefore most of the computing paraphernalia go into one unified block called the System on a Chip, or SoC.

91mobiles_Processor_101_cover

SoCs contain CPUs, GPUs, memory controllers and some wireless antenna such as Wi-Fi, GPS and cellular radios. More often than not, selecting a phone based on its processor can also impact the cellular data speeds which the consumer can avail, since different chipsets support different speeds and bands.

In essence, the SoC is the brain of the smartphone. When it comes to computing tasks, graphics processing in the form of images and videos, camera capabilities, gaming and even connectivity options, the basic fundamental is formed by the SoC.

Okay, so who manufactures these SoCs? 

The leading name in the SoC sector is ARM. The company itself doesn’t manufacture chipsets, but it licenses its production design to various manufacturers out there.

These manufacturers license out the ARM architecture, and comprise Qualcomm (for the Snapdragon lineup), Samsung (for the Exynos lineup), Huawei (for the Kirin lineup), Intel, Apple, Nvidia and Texas Instruments, among a few others. Other manufacturers, not linked with ARM, include the likes of MediaTek.

91mobiles_ARM_processor_types

The architecture followed by most popular processors (specially the Snapdragon series) include Cortex A series based processors such as the A32, A35, A53, A57 and A72 processors. The ‘A’ stands for application, and these processors are suited for multiple OSs and multiple requirements.

Hold up, what’s the difference?

The A series processors are fundamentally different from each other. The A72 is the current ruler of the roost, and comes bundled with the chipsets found within high-end flagships.

The difference arises in three major aspects:

• Size

• Performance

• Resource Optimisation

The smaller the chipset, lower is the power consumption. Performance comes from additional parameters such as floating point, integer and memory performance. And resource optimisation takes into consideration how efficiently the processor can handle major workloads.

91mobiles_Cortex_A57_vs_A72

These factors are reflected through benchmarking tests, such as AnTuTu, or Vellamo. These tests measure the overall performance of the phone and processor, and the scores obtained are cumulative sums of individual graphics processing and resource optimisation tests within the benchmark.

Isn’t there something about 64-bit technology…?

Yep, 64-bit processors are currently standard offerings within smartphones. 64-bit computing allows the processor to perform 64-bit integer operations. This allows access to more memory compared to 32-bit processors (which could only use about 3.5GB at a time), can handle more computations within a given time frame and enable better resource optimisation.

Advantages? More memory access would imply better multitasking, better workload handling and a smoother and faster experience for mobile users.

So the A series processors, can they be combined?

Absolutely, and that’s exactly what modern multi-core processors are all about. They have permutations and combinations to enable more performance based CPUs, and the combinations may occur in numbers of four (quad-core processors), six (for hexa-core processors), eight for octa and now even ten for deca (courtesy: the Zopo Speed 8).

More the number of cores (ergo the processors), better will be the resource-sharing capability. And with ARM based technologies such as big.LITTLE coming to the fore, there will be better workload sharing too.

91mobiles_ARM_functions_within_a_smartphone

At this juncture, there’s this myth we’d like to bust: more the number of cores, more the efficiency and performance? Not always.

It isn’t the number of cores, but the processor constituting the core, which makes the difference. For instance, the Snapdragon 650 processor powering the Xiaomi Redmi Note 3 is hexa-core, with four Cortex A53 cores, and two Cortex A72. The LeEco Le 1s runs on a Helio X10, which has eight cores, with eight Cortex A53 processors. Guess which one has better benchmark scores. It’s the Redmi Note 3.

What’s big.LITTLE?

big.LITTLE processing by ARM is a performance and energy consumption enhancement feature, found in more recent processors. Again, taking the instance of the Snapdragon 650 processor, this technology pairs a high performance processor (the A72) with an energy efficient one (the A53) along with dynamic task migration and resource allocation.

91mobiles_big_little

This system of heterogenous multiprocessing ensures that performance processors are reserved for more graphics intensive tasks (such as gaming), and other regular tasks (such as web browsing, calling and light usage) are handled by the energy efficient core.

Long story short, you get the best of both worlds: performance when needed, and battery life for a more prolonged use.

Alright, what’s the relation between processors and graphics processing?

This particular aspect is explained by the presence of the graphics processor, or GPU on board.

Performing any graphics task – from drawing a rectangle, initiating an animation and rendering graphics for games – requires the presence of a GPU. Additional functions include support for hardware-based encoding methods, and higher resolution video recording capabilities.

91mobiles_Processor_graphics

So, when we come across phones boasting 4K video recording capacities, or QHD displays, or dual cameras, know that the supporting mechanism comes in the form of a powerful SoC, with a powerful GPU on board. And more often than not, the support for such features can distinguish between a good SoC and a great SoC.

Got it. Last question: what’s clock speed?

Clock speed is a measure of the number of pulses per second generated by an oscillator within a processor. This in turn indicates the number of clock cycles required to execute a particular instruction, and perform a task.

Faster the clock speed (i.e more GHz), the more instructions the CPU can execute per second, and more performance-centric the processor might be.

However, there’s another rumour which we’d like to bust out here. A higher clock speed doesn’t always mean a better SoC.

Clock speed is definitely important, no doubt. But usually the requirement is of a more balance oriented, energy efficient experience, rather than a full-blown performance mobile. A suitable example in this case would be the Xiaomi Redmi 1S that came powered by a Snapdragon 400 clocked at 1.6GHz. Other phones utilising the same processor had clock speeds of about 1.2 - 1.4GHz, but Xiaomi had overclocked the CPU on the Redmi 1S, reportedly resulting into a a few heating issues. As we said, higher clock speed doesn’t always imply a better processor. Other factors such as the number of cores, and processor constituting the cores, along with the power balance come into play.

BTW, there must be some exception to all the myths being busted, right?

Well… yeah. That exception comes in the form of Apple devices.

The supporting point in this regard is the 2015 ranking of all the phones based on their AnTuTu scores, and the iPhone 6S Plus leads the fray. The phone has a dual-core A9 chipset, coupled with just 2GB of RAM. And yet, it beats much more powerful CPUs (at least on paper) with a modest combination of specs.

91mobiles_ANTUTU_benchmark_2015

The advantage comes in the form of the size of the chipset itself, along with certain optimisations between the operating system and the heavy duty cores.

So, what makes a good smartphone processor?

The takeaway point from this article? While choosing a phone based on the processor, two key factors that need to be considered include:

• The processors constituting the cores within the SoC.

• The support of the particular processor for multimedia and connectivity-based applications.

For a regular consumer, benchmarks might not be that significant, since they indicate the phone’s performance at a full-blown, high-end stage. Benchmark scores are good for bragging rights, but at the end of the day, it all boils down to regular usage and user experience.

(Image Sources: ARM, AnTuTu, Screenshot of Asphalt 8)



Comments (0) View All