The short answer is that while ARM is making inroads into areas traditionally dominated by x86/x64 like PCs and servers, a complete replacement is unlikely in the near future. However, ARM’s advantages in power efficiency and customizability make it a growing threat in an increasing number of applications.
Introduction to ARM and x86 Architectures
ARM and x86 are two fundamentally different CPU architectures that have their own strengths and weaknesses. Here’s a quick overview:
- ARM is a RISC (Reduced Instruction Set Computer) architecture originally developed in the 1980s for use in embedded systems and mobile devices. It excels in power efficiency thanks to its simpler instruction set and design optimized for low power consumption.
- x86 refers to the CISC (Complex Instruction Set Computer) architecture used in most PCs and servers dating back to the 1970s. x86 excels in performance through features like pipelining, branch prediction, and out-of-order execution.
Historically, x86 dominated personal computing while ARM dominated mobile. But as technological advances have blurred the lines between PCs and mobile devices, ARM has begun expanding into areas traditionally dominated by x86.
ARM’s main advantages over x86 include:
- Power efficiency – ARM CPU cores consume much less power than x86. This allows longer battery life in mobile devices.
- Customizability – Companies can license and customize ARM cores for specific needs. x86 is only made by Intel and AMD.
- Cost – ARM processors tend to be cheaper as they require fewer transistors. This makes them ideal for mass market consumer devices.
- Ecosystem – The ARM ecosystem has broad industry support with most mobile SoC vendors using ARM cores.
These advantages have allowed ARM to dominate mobile computing. As of 2022, over 150 billion ARM processors have been shipped compared to about 15 billion x86 processors. All modern smartphones, tablets, smartwatches, and other mobile devices use ARM processors.
ARM’s Push Into PCs and Servers
Buoyed by its advantages in mobile, ARM has begun pushing into PCs and servers which have traditionally relied on x86 processors from Intel and AMD.
For PCs, ARM-based processors from companies like Qualcomm, Samsung, and Apple offer longer battery life compared to x86. Microsoft also added ARM support in Windows to enable ARM-based Windows laptops. While performance is still behind top x86 chips, ARM’s progress in PCs continues steadily.
In servers, ARM is promising big power savings for large data centers. Amazon and Ampere Computing are releasing high-performance ARM server chips challenging incumbents like Intel Xeon. Although adoption is still early, ARM’s power efficiency gives it a major opportunity in servers.
Barriers to ARM Replacing x86
While ARM has made progress in PCs and servers, significant barriers remain before it can displace x86 completely:
- Legacy software support – Most existing software is designed only for x86. Emulation on ARM still lags native x86 performance.
- Ecosystem inertia – The existing x86 Windows/Linux ecosystem has huge inertia. Most companies are still conservative about adopting ARM.
- Performance – Top-end x86 chips still outperform ARM. Apple’s M1 is the first ARM chip to truly match x86 performance.
- Enterprise features – X86 offers mature enterprise features like ECC memory which are still developing on ARM.
It will likely take many more generations of ARM innovation before it can catch up to x86’s ecosystem maturity and top-end performance.
The Path Forward
Rather than a wholesale replacement, ARM is more likely to slowly gain share in specific segments playing to its strengths:
- Mobile and embedded devices – ARM will continue dominating this space where power efficiency is critical.
- Low-cost PCs and Chromebooks – ARM stands a strong chance here catering to basic computing needs.
- Specialized servers – For large data centers optimizing every watt, ARM can carve out a presence.
- High-performance computing – ARM is expanding into supercomputers and AI accelerators using its customizability.
But the scale and inertia of the x86 ecosystem means it will stay as the dominant architecture powering business PCs, high-end gaming rigs, and mission-critical servers for the foreseeable future.
Rather than a wholesale replacement, we are likely to see an increasing presence of ARM-powered devices co-existing and complementing the mature x86 landscape.
ARM’s power efficiency and customizability give it disruptive potential across a wide range of computing segments. But the massive x86 ecosystem is unlikely to be wholly replaced in the near future. A more gradual adoption of ARM in mobile, embedded, and select server applications is the likely path forward as the two architectures complement each other with their respective strengths.