If you are a personal computer/workstation user, chances are, at least once in your life, you have gone out to buy a processor, and odds are you returned home with one that was built by Intel. For a lot of people, there’s simply no alternative to Intel. Those who tend to be more open-minded and keep track of recent innovations, sometimes choose AMD. But whether you buy Intel or AMD’s processors, or the whole desktop in the same package, or simply a laptop, you’re basically using the same kind of processor, and that’s the 64-bit variant of x86 developed by Intel as early as 1978. You must have seen software programs labeled x86 for 32-bit and x86-64 (also commonly referred to as amd64) for the 64-bit variant. What these signify we will get into later; for now, suffice it to say it denotes a particular design of processors. So if both Intel and AMD (kind of the only potential rival) are developing the same kind of processors, are there even other kinds? Oh boy, is there!
In today’s world, even the non-technical internet users are familiar with “open source” software, i.e. software whose source code is made visible by its developer, often allowing third-party usage and modifications. As a matter of fact, the entire IT world relies on this kind of software program more than anything else. Companies like Google, Intel, AMD, Samsung, Facebook, and, to some extent, even Apple extensively rely on and support the development of the community-built programs. Servers are run on operating systems that derive their design from the old beast Unix, and these are the forerunners of the open-source development. Okay, I got that, you say, but open hardware? Can hardware even be open? If you’re trying to picture a computer with transparent casing, let me stop you right there. Open hardware means computer parts whose designs aren’t kept hidden by the organization developing it. If you were to build a processor the way Intel does it, you simply couldn’t, because you don’t have the design available. You could reverse-engineer, but in all likelihood, after you start selling your hacked product, there would be a knock on your door from angry lawyers. To eliminate that problem, and to make processor designs accessible to anyone wishing to learn about them, the RISC-V project began in 2010 at the University of California, Berkeley. Berkeley is widely known for developing the derivative of Unix called BSD, and now they are developing processor designs that are meant to suit all needs, from small embedded systems (think smartwatches or phones) to fast home computers to massive servers and supercomputers. And for this kind of ambitious and flexible design, they have chosen RISC—reduced instruction set computer. This is a different kind of approach than that of what you get with Intel or AMD, who use what is called CISC (complex instruction set computer).
While the term RISC might seem alien, if you own a phone, you’re already using a processor that uses the RISC (Reduced Instruction Set Computer) instruction set architecture. In the late 1980s, Intel saw massive profit with the rise of home computers and, along with Microsoft, they set out on a campaign to dominate virtually the entire PC industry. This has been so successful, in fact, people don’t even seem to be aware of alternatives, but it wasn’t always so. British mathematician (often credited with founding theoretical computer science) Alan Turing designed Automatic Computing Engine, which had a lot of technical features that would later be categorized as RISC. It was the dominant architecture developed by IBM, and they were highly successful throughout the 1970s and early ’80s. Up until 2006, Apple used IBM PowerPC, which is probably the most successful line of RISC processors in the personal computer world. First developed by Sun Microsystems (and then Oracle), the SPARC processors, introduced in 1986, are still among popular choices for servers. Even though Apple shifted to Intel as their supplier for desktop and laptop processors, for their iPods, iPhones and iPads they use the RISC ARM processors. Almost every Android phone Runs on ARM as well, and ARM is now the most successful example of the RISC instruction set. Compared to CISC processors like x86, RISC processors can be designed to consume much less power, perform faster in specific scenarios, and produce much less heat. (Have you seen your octa-core phone using any sort of cooler?)
But Will x86 Get 86’d by RISC-V?
Despite it’s historical success, RISC has admittedly been more confined to academia or special-purpose computing than mass home usage. Nowadays, apart from the ones written for phones, most of the operating systems and programs are first developed for the Intel and AMD architecture. How is RISC-V ever going to make an impact, when it’s not even the only RISC threat to CISC?
The answer is: because it’s open. While ARM is the dominant RISC architecture in the market now, it requires a license fee to manufacture the processor. They strictly guard the designs. The same is true of another RISC-design processor called MIPS. Such a tradition prohibits widespread adaption. On the other hand, RISC-V has a design which is licensed under the permissive BSD license, and anyone wishing to use that design can do so without paying anything. Some manufacturers have already started building RISC-V processors for various uses, most notable among them being the Chinese group Alibaba, who is reportedly working on Xuantie 910, claimed to be the “fastest RISC-V processor in the world” with 16 cores clocked at 2.5GHz. Plans regarding this have no doubt gotten postponed by the tragic outbreak of Covid-19, but the fact that China has been itching to overthrow the USA’s monopoly in processor manufacturing is old news, and RISC-V gave them the perfect opportunity to implement an already-existing superior design. It has been rumored that Huawei has had their eyes on RISC-V for a while too. Whenever things should get too hot with Arm Holdings, Huawei can just abandon their proprietary processor design and start building the company’s own RISC-V processors for phones and tablets. SiFive is a company that manufactures RISC-V processors on-demand, so should someone really want it, RISC-V isn’t just a theoretical idea on paper. It actually exists.
It’s true that none of these actually pose a real threat to Intel or CISC architectures in general. But in the past two decades, the computing world has drastically changed. The home users for whom the desktop was the only means to using a computer, connecting to the internet and doing office work, are now using their smartphones and tablets more than any other device. As for laptops, the frustrating battery life you could get from an Intel processor has started to become an issue for more and more people. “Heck, I can go over 24 hours on a single charge with my tiny phone, why can’t I push it any more than 12 hours on a heavy burden such as my laptop?” As mentioned earlier, RISC processors consume less power, and some laptop vendors seem to be waking up to that fact, as well. And less power consumption means less heat, and that translates to a fanless design which would be much lighter than Intel/AMD laptops.
So maybe not anytime soon, but a freely-available processor design, something which has historically been kept under lock and key, can bring out a revolution. Not to mention free and open-source software projects like Debian and FreeBSD already support RISC-V. When the hardware reaches the user, there’s no need to wait for the right kind of software to arrive.
Like the free and open-source software projects, RISC-V is built with the community in mind. I can’t help but remember when Microsoft ridiculed GNU/Linux throughout the ’90s and early 2000s. Not long after that, they started offering “compatibility layers” for this community operating system (basically the ability to run GNU/Linux or other Unix-like systems within their own OS). The computing world is a massively-changing one, and the user community ultimately decides who rules.