Changes brought about by the rise in cloud computing have had a huge impact on servers and server design, and could be the key factor in bringing ARM's low-power RISC chips into the datacentre.
ARM believes that the rise of cloud companies like Facebook, Google and Amazon is bringing about a change in attitudes to processors that could make its chips relevant for these companies, posing a potential threat to Intel and AMD's server businesses.
Over the past few years, "the nature of servers has changed," ARM's general manager of its processor and physical IP divisions, Simon Segars, told ZDNet this week. "It's really the growth in cloud [and] growth in companies doing web hosting [and] social sites. As that has grown the nature of servers has changed."
These workloads place the emphasis on light computing tasks but with lots of parallelism and frequent use of large amounts of data, Segars said. Because of this, people are becoming ever more concerned with the power consumed by each individual processor, and this could bring ARM chips into the datacentre.
Companies want the thermal design power - how much power, roughly, a chip uses - to be "as low as possible," Segars says. ARM's chips, which sit at the heart of the vast majority of the world's mobile phones, including Apple's just-released iPhone 5, consume much less power than Intel's processors.
Calxeda's EnergyCore ARM server consumes around 5W, and the company published the results of an ApacheBench benchmark in June that showed its technology beating a 102W Intel Xeon processor.
Over the past few years, ARM has been developing new chips that are designed for servers as well. In October last year, it announced a 64-bit design. 64-bit is considered to be a must-have feature for servers, so in about a year when ARM licensees start churning out the processors, big things could happen in the datacentre.
This change will be driven by the "mega-trend" of the growth in data-intensive mobile devices, like smartphones, Segars said. "A lot of those data services can be streamed by ARM-based servers."
The counter argument to ARM's is that Intel has years of experience of building server processors and has developed a large amount of x86-specific technologies to support server workloads.
Another one is that as ARM designs new chips for the datacentre it will have to put additional features into the processors, which will lead to a rise in the amount of power consumed.
Meanwhile, Intel is preparing to launch its Haswell processor, which will consume as little as 8W of power, taking a high-end compute chip into territory typically occupied by ARM.
Furthermore, ARM has less broad support for the types of software that run on servers, though Segars notes this is changing: "In the server space the Linux kernel has been optimised for ARM for many years," he said.
For the small and medium business there is no evidence that ARM chips have a credible play there, with these companies typically preferring x86 servers from major enterprises like HP, IBM and Dell due to a combination of the Intel processors, comprehensive service and support contracts, and the related software ecosystem. There is not really an equivalent ecosystem of software for ARM yet.
ARM gambles on success in the major clouds
ARM's bet, though, is that the very large cloud operators - Google, Amazon, Facebook - could be tempted by its chips due to the impact it will have on their datacentre electricity bills. Over the lifetime of a datacentre, it's typical that at least 50 percent of the cost of the facility comes from the electricity it uses, so driving this down is a priority for these companies.
Related to this is the rise of software-as-a-service tools for small businesses like Salesforce for CRM or Microsoft Office 365 for productivity. Adoption of these tools means businesses have less need for hardware themselves and instead outsource the capital cost to a cloud operator.
"If you're focused on being a dental practise of a hospital, the last thing you want to do is manage IT," Ian Ferguson, ARM's director of server systems and ecosystem, told ZDNet. "Fundamentally those guys aren't going to be buying as much IT equipment in the next few years."
Whether ARM's chips have what it takes will become apparent over the next couple of years as 64-bit designs come onto the market.
"I think you can regard ARM in the cloud as a player in 2014," Ferguson said. "There are trials going on in end users right now. I think those will start to translate to volume in that sort of timeframe... it takes some time to get the silicon right, to get the platforms right, and on 64-bit we've got to get more of an ecosystem going."