Customization, costs key to Linux HPC dominance

Many of today's top supercomputers are running on Linux operating system (OS) as their users prefer the open source software's flexibility in customization as well as low costs compared with alternative proprietary OSes, observers said.

According to the Top500 Supercomputer Web site, which tracks the latest happenings in high-performance computing machines, Linux OS constituted 82.8 percent of all supercomputers, with the next OS, AIX, coming in at a distant 5.6 percent as of November 2011.

The open source OS has come a long way since it first overtook Hewlett-Packard's Unix system to be the leading platform in June 2003. Then, Linux had 27.8 percent market share, with Unix taking 24.6 percent, according to the Web site.

Stephen Wong, deputy director of computing systems at Singapore's Agency for Science, Technology and Research (A*Star) Computational Resource Centre, said that Linux's dominance in the supercomputer arena is no surprise.

Since it was first introduced in 1991, Linux software has quickly endeared itself to the open source community, he told ZDNet Asia in an e-mail. By early 2000s, vendors have started to take note of Linux as "a force to be reckoned with" and began incorporating the OS in their product lines along with Unix, he added.

"[Now,] many supercomputer centers prefer Linux to traditional Unix because the open nature of Linux allows them to customize the OS to their operational requirements," Wong explained.

Linux also allows vendors to build a price-competitive machine faster than when using proprietary operating systems, Amanda McPherson, vice president of marketing and developer programs at The Linux Foundation, pointed out.

The executive said in her e-mail that supercomputers are generally custom-designed and deeply tuned for the specific workload, very expensive, and have low sales volumes. This is why the open source operating system's low cost appeals to IT vendors.

"With Linux, anyone can see and optimize the source code, and work done by one company can be extremely beneficial for others. After all, about 90 percent of the kernel is architecture-agnostic. When selling a supercomputer, the time to first boot is critically intertwined with profitability," McPherson explained.

By contrast, commercial servers are like assembly lines where vendors figure out what the customers need, pick a suitable OS and system, and churn out machines that are optimized for most of the identified workloads, she said.

"You try to make your money by selling a lot of them as fast as possible, and without having to do much customization to keep your customers happy," the vice president added.

Such a business model means proprietary OS vendors would find it difficult to keep up with supercomputer developments and demands, McPherson said. As these vendors have only a limited number of developers focused on servicing their core commercial server market, this means vendor support in terms of customization will be lacking, she noted.

Besides, Linux evolves more rapidly than other OS and diversifies faster because of its open source nature, she said. "No other operating system has jumped to new platforms, workloads and architectures so quickly. As a result, Linux tends to get new features and functionality sooner than the other options and on a wider variety of platforms."