Power efficient processors aren’t just for smartphones | andropet
PO Box 71853
19193087597 durhamblues@gmail.com

Power efficient processors aren’t just for smartphones

By Team AA

The smartphone market is powered by power efficient processors, enabling our handsets not only to pack in enough performance to run our favourite apps, but also operate in a low enough power profile to support high resolution displays, mobile networking, and an array of sensors all from a small phone battery to last all day. These benefits can also apply to larger screen products, with tablets and Chromebooks offering up similar features and excellent battery life. The same features would no doubt also fit well into mainstream PC products to deliver that smartphone responsiveness. However, x86 processors from legacy manufacturers currently make up the bulk of this market, but these chips aren’t very well suited to the low-power requirements while delivering the performance that smartphone users have become accustomed to.

We saw these players unsuccessfully dabble in the handset market back in 2014. However, higher than typical battery consumption and hotter components in a thermally constrained environment resulted in poor performance, and the x86 architecture ducked out of the smartphone market after just a couple of years.

Fortunately these problems don’t apply if we reverse the situation. Low-powered processors are quite well suited to certain large screen applications. Especially given the year-on-year performance improvements that Arm architecture has seen in recent generations. CPU performance is up 300 percent over the past 5 years after factoring in process improvements, and the latest Cortex-A75 promises an extra 30 percent additional performance for large screen form factors with a larger power budgets. GPU performance has pushed ahead even further, up 1000 percent over the same period.

As well as tablets and laptops, we’ve recently seen smartphone manufacturers make the move into the large screen space. Samsung’s Dex and Huawei’s PC Mode offer up large screen desktop environments for enterprise users running on their phones’ internal mobile processor, so there’s no performance augmentation in the dock.

The only potential hurdle to expanding this opportunity further is one of architectural compatibility. Arm’s Armv7 and Armv8 architectures aren’t compatible with x86 instructions, meaning that extra work has to be done on the software side to ensure that existing products work across different hardware bases.

CISC vs RISC returns

One of the key difference between Arm and x86 is that Arm designs a Reduced Instruction Set Computer (RISC), while the x86 architecture is a Complex Instruction Set Computer (CISC). CISC offers up high peak performance by using a single instruction to execute multiple tasks, such as arithmetic and load store, but such variety increases the number of instructions. RISC aims to stick to a smaller number of general instructions, but the benefit is that power consumption remains much lower as there are fewer memory cycles per instruction.

In the early days of computing, RISC and CISC served different purposes due to their capabilities and power requirements, hence why RISC was much more suited to early smartphones. But the gap has been narrowing in many ways, and the terms are now more blurred than ever. Many RISC instruction sets, including Arm’s, have grown in size to offering better performance at many tasks (there have been several RISC-based supercomputers), and the benefits brought about by more advanced manufacturing techniques have boosted not only energy efficiency but also processing performance.

Arm’s scalable footprints offers the option to expand CPU designs into different form factors and products with various thermal requirements, providing a range of energy and performance options.

The other equally important advantage that RISC maintains over CISC is silicon area. A smaller silicon footprint results in cheaper processor production and therefore lower cost products for consumers. A small but scalable footprint offers the option to expand CPU designs into different form factors and products with various thermal requirements, providing a range of energy and performance options. In other words, RISC scales well from low power smartphones up to higher performance laptops and large screen devices

In today’s world of consumer computing, there’s now a large amount of crossover between RISC and CISC in terms of capabilities, and both certainly meet the performance requirements of the most common consumer tasks for multi-tasking across common consumer use cases, enterprise and productivity, all the way up to casual and high-fidelity gaming. We’ve already seen low power laptop processors developed by some of Arm’s partners, including MediaTek, Rockchip, and Samsung, among others. These chips have and continue to power tablets and Chromebooks, and will soon be powering other large screen devices too.

An opportunity with Windows 10S

Platforms and operating systems should be processor architecture agnostic these days. Google’s Chrome OS, essentially Linux with a built-in full browser that powers its Chromebooks, runs on both x86 and Arm-based hardware. Google has even added in support for Android apps on the platform, regardless of processor, using Android Framework running in a container, much like virtualization. Power efficiency focused Chromebooks have already proven more than capable at web browsing, hosting a full suite of office applications, and even running more demanding Android apps.

Microsoft is promising similar hardware compatibility with its upcoming Windows 10S laptops support for Arm hardware with Windows 10. In order to run the full Windows desktop experience on Arm processors, Microsoft created a transparent ‘just-in-time” transcoding emulation layer to convert x86 instructions to Arm ones. The technology is based on Microsoft’s Windows on Windows technology that runs 32-bit apps on 64-bit machines. This process only needs to be done once, so there’s no lag or delay when booting up applications a second time. The company’s Windows 10S laptops, which are streamlined models for security and performance, will be the first of these new products to support both Arm and x86 processors. Microsoft has already shown off Photoshop running in real time on a Qualcomm Snapdragon processor, so again performance is looking promising even for more demanding applications.

Microsoft recently claimed that upcoming Arm-powered Windows laptops will offer multi-day battery life too, a game changer for …read more

Source:: android authority