high-performance computing
➤ rating peaks at about 130W or 150W; and it is probably too expensive to retrofit a data centre for liquid-liquid cooling at this level, Vuckovic explained. But above 200W, liquid cooling is needed. In between, air cooling will result in hot spots as some processors are not cooled as well as others. ‘In the middle you have some sort of a gap. To avoid the piping, you want to use air at the rack level but liquid inside the server only. You might be willing to use an intermediary solution. So we can handle high-power loads without the hot spots’. Whereas the fluid to water system was customised to customers’ requirements, the liquid enhanced air cooling system will be a standardised, commoditised product.
Game on Asetek and CoolIT Systems also offer closed loop systems, this time using water to cool the processors. Te antecedents of both companies are in gaming, in providing a way to overclock the processors and rejecting the heat
to the air at the back of the PC. As a result of its origins,
CoolIT has shipped more than two million units of its cooling system, mainly for PCs, according to Geoff Lyon, the company’s CEO and CTO, and it expects to ship between 250,000 and 300,000 this year alone. Tis background allows the company, based in Calgary, Canada, to benefit from economies of scale and also demonstrates the reliability of the technology. Lyon pointed out that no-one in HPC had ever disputed that liquid cooling was efficient, but he feels it is now becoming more widely accepted. Part of the reason is that early adopters in HPC now have some years’ experience of the technology. More than 30 installations world- wide have installed CoolIT’s technology, he continued: ‘Te number of our installations has more than doubled this year. We’re being run off our feet.’ He expects the HPC and datacentre markets to outstrip the desktop in importance. Te gaming market is highly competitive, he remarked, and margins are low He also said that vendor
motivation is now apparent – IBM has had liquid cooling for some years, and the HP Apollo line is unique. Systems integrators are starting to specify liquid cooling in their request for proposals – especially in Europe, as a result of the price of electricity. But the advent of Big Data is a game changer, he believes: ‘On the surface, HPC is fast growing, but Big Data combined with HPC is a fantastic growth opportunity.’ Some of Lyon’s analysis of
The inside of a node in the cluster at Kyoto University, showing CPU and memory cooling
customer requirements mirrors that of Calyos’s Vuckovic: for instance, in the need to have an intermediary solution for those facilities that could not, or did not think it cost effective to, install an entirely water-cooled system. ‘Some people are in too big a hurry to wait for facility water supply to be plumbed in,’ Lyon said. He also noted that ‘coordinating the facilities
28 SCIENTIFIC COMPUTING WORLD
An Asetek liquid-cooled Cray at Kyoto University with its doors open revealing the RackCDU and connecting tubes to the nodes
budget and the budget for IT was not always smooth’ and the administrative split between them oſten determined what cooling solution was put in place. Te company developed one
product line, the AHx, for its own test laboratory. It is uses the company’s Direct Contact Liquid Cooling to dissipate heat to the surrounding environment via a liquid-to-air heat exchanger at the top of the rack. It comes in two varieties that can manage 20kW or 35kW of processor load respectively, without the need of facility water. However, he continued, almost
without exception the ambition of their customers is to upgrade to a liquid-liquid system. Te company therefore offers the CHx40, which provides water to water heat exchange capable of absorbing up to 40kW from one rack, and it also offers a networked system, the CHx650,
system which distributes clean, treated coolant to and from many IT cabinets at once, accepting warm facility water at the inlet, and managing 650kW of processor load per network.
Cheap to build and to run For Steve Branton, senior director of marketing at Asetek, it is not just the inlet temperature that is important but the outlet temperature as well. Te outlet temperature of 55C means that heat can be recovered for heating the building. He cited the case of the University of Tromso in Norway where, at the Arctic Circle, there is a demand for building heating all year round: ‘so they get double use out of their electricity by capturing the heat’. In a system installed at the US National Renewable Energy Laboratory (NREL) in Colorado in 2013, the heat is used for snow ➤
@scwmagazine l
www.scientific-computing.com
Asetek
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56