3 of 8Image
Of course, not every datacentre can be built in chilly climes. "The latency is the problem; the delay. A lot of companies have to have datacentres located near their work, and in the country", Schmidt says. Some places, for example, mandate that data cannot leave the country for data protection reasons.
But even if a business is located in a warmer climate, its datacentre can still tap into its surroundings, partly because the industry is moving away from the notion that datacentres have to stay nicely chilled. IBM's chips, Schmidt says, are designed work in temperatures of up to 85°C (185°F). Keep the equipment below that, and it should work just fine.
It follows, therefore, that you can use outside water at ambient temperature to chill your datacentre - creating the seemingly paradoxical notion of 'hot-water cooling'. "Like the air cooling... why can't we use the outside water to cool?" Schmidt says. The advantage, of course, is that if you can use water at ambient temperature, you're not using energy to chill it first.
Some of the company's x-series mainframes have inbuilt water-cooling with a water temperature of 45°C and IBM is looking to push the water temperature for cooling even higher, to around 65°C: "What we've been talking about is using the water to cool the chips, then it goes through the system and comes out hotter, maybe 70°C, and we use that hotter water for the heating of buildings and central distribution in towns," Schmidt says. "There's a lot of interest in this because we've never really been able to solve the waste heat problem for datacentres. So now we use hotter water, we can use that waste heat for good purposes."
The principle is illustrated above: the dial on the left shows the temperature of the water coming in from the Hudson River, just outside the IBM plant. The right-hand dial shows the water temperature on the way out, after it has collected heat from the datacentre.
Pictured above: water-cooling at IBM's Poughkeepsie datacentre.
The green datacentre is a working facility, processing jobs for IBM customers and Big Blue itself.
Three years ago, the facility was running out of space and suffered cooling problems. Rather than build a new centre, IBM called in a team of designers to remodel the space, and in the process created a showroom highlighting datacentre best practice.
Some of the measures it took are startlingly low-fi: brushes around pipes, for example, stop air escaping; bendy underfloor pipes mean the water-cooling configuration can be changed at any time; and the air vents in the floor are different sizes for the air-cooled side and the water-cooled side, according to which needs more ventilation.
In the back room, there's a sub-station that allows DC electricity to go straight into the equipment without conversion. "There's a lot of discussion in industry: why do we need all these conversion paths all the way through: DC to AC, AC to DC?" Schmidt says. Each conversion loses energy along the way, so plugging DC straight into the datacentre avoids that leakage. "We've now certified some of our high-end systems [for DC power]."
Cabinets are fitted with rear-door heat exchangers, which suck in the hot exhaust air of the servers and blast it out again as cold air. The technology - the IP is owned by IBM - can take away up to 60 percent of the heat in a full rack, the company claims.
The result of these changes is a datacentre PUE (power usage effectiveness) of 1.27, which generated a return on IBM's investment within 10 months.