Recently, Qualcomm announced that it will be looking to design Apple M1-like devices for Windows PCs. Why is Qualcomm looking at the Apple M1 as a solution for Windows, what advantages does an ARM-based computer have over traditional x86 computers, and will x86 devices eventually be phased out?

Qualcomm looking at M1-like SoCs for Windows

The Apple M1 SoC demonstrated a significant shift in technological development. It marked the first time a large computer equipment manufacturer decided to move away from conventional off-the-shelf CPUs and instead chose to develop their own architecture from the ground up. The use of ARM CPUs along with computing cores designed explicitly for unique tasks (such as AI) created a processor whose performance completely outshone anything developed by other processor manufacturers.

However, caution should be exercised when using the term “performance” as this can mean many things. In the case of the M1, its processing capability still pales compared to a top-end Intel processor. Still, the power to performance ratio (i.e., the energy consumed to perform a task) is significantly better. This reduced energy usage allows Apple devices to improve their battery life while providing far more processing power, something that is ideal for mobile applications.

Recognising this achievement made by Apple, Qualcomm is now looking towards creating an M1 equivalent for the Windows market that could help create energy-efficient Windows devices while providing excellent performance characteristics. The division of Qualcomm, called Nuvia, will be using ex-Apple engineers to develop a SoC that will help realise this vision. At the same time, Microsoft continues to develop ARM support for future operating systems.

In a recent conference, Qualcomm said that some of the fastest PC architectures in use are based on ARM technology. Still, the lack of interest in ARM technology for PCs is holding back its development. Furthermore, Qualcomm also acknowledged that the mix of CPU architectures available means that programs designed to run on one run significantly slower when run on a different architecture under emulation. But this won’t deter Qualcomm, who also plans to introduce ARM silicon into datacentres and servers.

What advantages does ARM-based PCs have over x86?

Comparing x86 to ARM is somewhat tricky as each processor architecture is fundamentally different; x86 is a complex instruction set that aims to create powerful instructions that are easy to program, while ARM is a reduced instruction set that looks to create very simple CPUs (in hardware).

Another way to look at it is that x86 is a powerful engine that consumes enormous amounts of fuel to provide massive horsepower. At the same time, ARM is a small engine that doesn’t produce much horsepower but uses very little fuel in the process. If both engines are used in the same task, the x86 will do it in a shorter time, but the ARM will do the task using far less fuel.

But the advantage that ARM provides to computer architectures is not in its speed of the execution but in the fact that engineers can integrate ARM cores into custom silicon devices and then build peripherals on top of this. By only choosing the peripherals that the computer needs, combined with the smaller ARM cores, an extremely energy-efficient processor can be built that can perform the same tasks as x86 CPUs but using a fraction of the energy.

The physically smaller ARM cores also make it possible to have processors with far higher core counts. While these cores will be far less powerful than any modern x86 core, they are still powerful enough to run everyday tasks, including web browsing and word processing. This means that a many-core ARM processor could run tasks in parallel very efficiently while showing no slowdown in performance.

Another major drawback for x86 is that it is focused on backwards compatibility meaning. This means that portions of modern x86 processors are dedicated to executing code written in 1980, which is not efficient silicon space. ARM, however, is constantly being updated and revamped while supporting a limited number of instructions. The result is that hardware designed around ARM processors can modernise more easily than x86 designs, which fundamentally have to be backwards compatible.

Will ARM replace x86 in the PC industry?

The x86 architecture has been a favourite by the industry simply because of its widespread use, its ability to make programming easier (being a CISC CPU), and its raw processing capabilities. However, the world continues to move towards mobile devices where energy efficiency is paramount. Intel and AMD devices are not the most energy-efficient (many call AMD processors toasters due to the large amounts of heat they generate when under load).

The Apple M1 proves that ARM processors can be used in a PC environment that Qualcomm has recognised (consider that Qualcomm specialises in energy-efficient mobile SoCs). Of course, this does not mean that ARM will replace x86, but it does beg the question if Intel’s famous x86 architecture will eventually be replaced with something more suited for current times.