Understanding power density in the data centre

Advances in technology have made microprocessors more capable and energy efficient than ever, allowing a new server today to significantly outperform one that is just a few years older. Yet, demand for more powerful compute infrastructure is showing little signs of slackening, as enterprises seek to establish their own private cloud infrastructure and blend it with the public cloud for an optimal mix of control and cost.

One effect is the increasing popularity of high-powered hyperscale hardware, which offers cloud-like levels of scalability and manageability to help organisations quickly roll out private clouds. Unsurprisingly, these high-density servers and networking appliances are placing greater demands on power supply as they make their way into data centres.

In some quarters, this has raised questions as to whether older facilities can adequately support the new generation of high-powered infrastructure. We take a closer look at how data centre operators typically meet increased power demand to better understand the merits of such concerns.

It should be noted that supporting high power density is completely doable even in legacy facilities. Under the hood, this is typically achieved by siphoning power from surrounding racks, leaving them with reduced power or completely unpowered. The downside is that the former strategy requires the right mix of customers, while the latter necessitates factoring in the empty racks into the cost of supporting the new high-powered racks.

It is worth noting that higher power density is not solely related to electrical loading – it is also about ensuring the availability of sufficient cooling capacity. This could entail the installation of additional equipment to deliver the requisite cooling, again at the cost of data centre space. Depending on the projected power requirements, however, there may be situations where existing cooling infrastructure simply cannot cope with what is required.

Of course, an obvious method of addressing the abovementioned issues is to design the entire data centre to support a high power density environment from the get-go. Yet, it makes little sense to incur the cost of catering to workloads of 10kW or more per rack across the entire data centre when the average power demand in Singapore is around 5kW per rack.

While impressive from a marketing perspective, such a data centre would unfairly penalise customers without high power requirements. Specifically, customers who deploy more network equipment or ordinary servers, could end up subsidising those looking to deploy higher powered equipment.

One solution offered by Singtel’s $300-million DC West data centre would be its ability to handle up to 8kW per rack without the need for special cooling. This would be adequate to accommodate the vast majority of existing use cases.

For users with higher power needs, sections of the data centre will be capable of delivering the requisite power and cooling infrastructure as required. The result is greater versatility to accommodate the power demands of the future, but in a manner that better aligns with current market realities and demand. 

Read more about DC West here.