POWER compares favorably to x86 platforms like Xeon and EPYC. POWER also runs Linux distributions quite well while giving you the added advantage of a computer architecture designed from the ground up for enterprise systems. It features all the enterprise performance options you’ve come to expect from x86 server systems while simultaneously reducing overall costs.
The complexities of running POWER on Linux
You might think that running Linux on a POWER server would be more complicated, but it’s not. Note that the specific ISA of POWER that you’re using will affect your ability to run Linux. When running Linux, there are various POWER architectures you’ll need to consider. Unfortunately, not every architecture will be compatible with the version of Linux you are running. Before testing, verify that your architecture is compatible with POWER.
The modern systems are POWER8 and POWER9, which are modern interpretations of POWER found in both enterprise servers and supercomputers, alike. The most powerful supercomputers currently available in the United States are all running on POWER. They also run a specially modified Linux operating system built for supercomputing and high-performance computing.
What developers need to know
Endianness is the only thing that developers have to worry about when developing with POWER. The way that x86 represents data is fundamentally different from the way that POWER does. This difference in data representation caused POWER to suffer from a lack of software support.
Unfortunately, it costs a substantial amount of money to hire programmers to rewrite software in a way that promotes compatibility with the architecture. However, starting with POWER8, IBM produced versions of POWER with little-endian support. The end product was very comparable to that which is available with x86, meaning developing software on both platforms is fundamentally the same because there is a large pool of open-source software that developers can look at to gain insights about writing programs for POWER.
The major Linux distributions all support POWER, such as Red Hat Enterprise Linux, Ubuntu, Fedora, and SUSE Linux Enterprise servers, which all run on modern and even older versions of POWER. With this universal support of POWER in mind, you can access almost the entire library of programs written for Linux.
POWER has the advantage of being a superior architecture compared to x86, as it’s a lot leaner and agile so that the code executes better. With POWER, there isn’t a lot of legacy code to weigh it down. While x86 does a lot to maintain backward compatibility, POWER doesn’t face these constraints, and you’ll still receive the same benefits of backward compatibility that you do with x86.
Virtualization on POWER
The only area where running POWER might suffer compared to an x86 system is in virtualization. The default virtualization option for most distributions is KVM. There is also PowerVM, but this option only caters to a select few distributions. The performance of these virtualization options will often lag behind x86 options. If you’re running POWER in a virtualized environment, you might need to do extra work to keep everything optimized compared to competing options.
Choosing a distribution
Not only is running Linux on POWER a great option, but it affords the users the same choices they’d receive with x86. You can choose from distributions like Ubuntu, Red Hat Enterprise Linux, and SUSE Linux. Each distribution will operate differently, so your final decision should depend on what you are trying to achieve and the programs you need to run. The environment you are familiar with should also influence your decision.
Overall, the performance will be the same as most of the underlying software will be the same. For example, the Kernel and the windowing software are identical. It will either be KDE or Gnome. Functionally, there will be no difference between running POWER on any of these distributions.
Example uses of Linux on POWER
Running Linux to manage enterprise software is an example of the use of POWER mainframes IBM also used this architecture to power its Watson supercomputer. It’s the same supercomputer that competed and won on Jeopardy. The architecture has evolved since then and will continue to be an MVP player in the Linux ecosystem.