ARM's power advantages over typical x86 chips from Intel and AMD will continue for around half a decade before fading away, according to AMD.
Yesterday, AMD announced it would start making ARM-based servers in 2014, and today Suresh Gopalakrishnan, general manager of AMD's server business unit, told ZDNet that ARM's power advantages could be short-lived.
"If you increase the capabilities of the [ARM] processor, it will consume more power. At the same time, if you start working on the [x86] architecture and process together you can bring the power down as well," Gopalakrishnan told me. "Right now ARM has the [power] advantage - five years down the road we'll see."
In the future, Intel will bring in new energy-thrifty chips built on its advanced 14nm and 10nm fabrication methods, which will help it lower their power consumption, while ARM's chips will consume more power as more features are added to them to let them tackle more advanced server workloads.
So, in a few years, the power advantages which are propelling ARM's chips into cloud datacentres like Facebook's could fade as technological forces conspire to close the gap in electricity usage.
Why is AMD licensing ARM for servers now then? Because it can bring the 64-bit chips out years before the power window closes, Gopalakrishnan said.
Along with this, by pairing ARM chips with a dense networking fabric, like AMD SeaMicro's Freedom Fabric, there's a chance to create some novel server designs: "You will see very dense clusters tuned towards a certain class of workloads," Gopalkrishnan said. Some of these workloads will be ARM and some will be AMD.
As AMD says, the future is 'ambidextrous' and from 2014 it's going to have an x86 hand and an ARM hand. However, for how long this will remain is a mystery if the power advantages disappear.