Published in Military & Aerospace Electronics
Written by John Keller
Military embedded computing systems based on bus-and-board architectures are advancing quickly on three fronts: data throughput; thermal management; and standards-based designs. These three technology trends promise to bring the latest advances in high-performance computer processors to demanding applications like electronic warfare (EW), signals intelligence (SIGINT), and radar signal processing.
Ruggedized embedded systems enclosures certainly are important, but do not represent the latest trends in embedded systems chassis and databuses, which increasingly reflect new open-systems standards, blended optical and copper interconnects, and electronics cooling approaches to deal with computer boxes that can generate in excess of 2,000 Watts.
It’s all part of the latest trends in databuses and enclosures that will produce some of the most powerful embedded computing systems ever developed, which will be designed to accept rapid upgrades, accommodate rapid changes in technologies, and bring server-grade computing to ruggedized digital signal processing systems aboard aircraft, on ships and submarines, and on the latest armored combat vehicles.
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Thermal management
All of these increasing speeds, however, mean generating a growing amount of system heat, which puts pressure on design engineers to devise innovative means of electronics cooling. “The power consumption in these systems is getting much higher — to the point where the P-zero connector at these lower voltages can only handle so much,” points out Pixus’s Moll. “Power limitation right now is an issue that is coming up, and sometimes we have to put in a special connector to get enough power on the backplane.”
GMS’s Ciufo characterizes the thermal management challenges that today’s embedded computing designers face. “Processors are consuming more and more power and generating more and more heat. We have been introducing rackmount servers, starting with the Intel Xeon E5, and upgraded to the new Intel Xeon Scalable processor and second-generation Scalable processors.”
Yet the heat continues to rise, he says. “Intel’s latest and greatest middle-of-the-road 20- and 24-core Scalable processors consume 150 Watts per processor,” Ciufo continues. “Our systems have two to four processors, so easily it can get to 300 Watts for only two processors and 600 Watts for four processors.”
Still, today’s leading-edge embedded computing systems rely on more than just processors. “Add two artificial intelligence cards from Nvidia is another 500 Watts — 250 Watts per processor. These systems easily are consuming in excess of 2,000 Watts and more. No longer is it trivial to air-cool rackmount servers, so we have stepped-up or game.”
It’s not just GMS that must step-up its game, but also every other high-performance embedded computing designer who seeks to serve this market. “Cooling is kind of the tool kit,” says David Jedynak, chief technology officer at the Curtiss-Wright Corp. Defense Solutions division in Ashburn, Va. “There is no new physics to magically cool things. At the chassis level, the thermal design can be very focused for the type of platform, but on the board, there are only a few ways we can cool them.”
For GMS air-cooled chassis and enclosures “we have taken a page out of the VITA 48 playbook, to make sure we are doing managed airflow — essentially to make certain we can cool systems that in excess of 2,000 Watts,” Ciufo says. “We are doing computational fluid dynamics to make sure the air moves where it needs to and moves the heat out of the back of the chassis.”