British cloud hosting company Memset claims to have proved it is possible to reduce power consumption faster than Moore’s Law.
Moore's Law is a rule of thumb whereby the number of transistors that can be placed on an integrated circuit doubles every 18 to 24 months. It is also a good approximation for the rate at which energy efficiency improves, according to Memset, because when computers are viewed overall, their performance per watt roughly doubles every 18 months.
The company carried out the research in collaboration with Surrey University by examining the load levels and power consumption of its own Miniserver VM host server estate. Each server has one 0.7GHz Xeon core, 1GB RAM and 80GB RAID1 HDD.
The average power consumption of Memset's Miniserver VM virtual servers in mid-2009 was 26 watts. According to Moore's Law, those VMs should have been using 6.9 watts at the end of 2011. However, by refining and tuning the host hardware to optimise it for the actual load profile, Memset has been able to reduce the average power consumption a further 47 percent, to 4.7 watts.
“It's optimisations in things like the ratio of CPU to RAM, the type of hard disks we use, the way we load different numbers of virtual machines onto the hardware, getting rid of bottlenecks,” explained Kate Craig-Wood, managing director of Memset.
“The important thing is we haven't actually invested in any clever fancy technology. We're using very standard off-the-shelf server components, and we've just found the sweet spot.”
The refinement is an interative process, according to Craig-Wood. Memset monitors the power consumption of all its machines and periodically performs analysis on them to find out which resources are the most strained, before proposing the next generation of host architecture.
She added that CPU is generally under-utilised, even after virtualisation, and that it is RAM and disk transactions that tend to be limiting.
“We still find customers tend to request not enough RAM but too much CPU,” Craig-Wood said. “Everyone assumes you need computation, but most of the tasks that we want computers to do are around manipulating data and databases, or getting data in and out of systems. That doesn't require any computation, there's no complex algorithms running behind the scenes, it's basically shuffling bits around.”
Memset claims this research is proof that ICT can deliver on its promise of a greener society without itself becoming a major indirect source of greenhouse emissions. It also indicates that you do not need to be operating at mega scale to be able to be efficient, said Craig-Wood.