COTS delivers high performance and low powerStory
December 09, 2010
A typical off-the shelf SBC dissipates 35 to 75 W, ultimately reaching more than 100 W when tucked into a subsystem; however, low-power processors like the Atom can cut power dissipation by a factor of three, while proffering Celeron or Pentium M performance.
Minimizing Size, Weight, and Power (SWaP) is one of the most critical requirements for deployable military equipment. Power dissipation is the key factor that drives both size and weight, as heat requires either space or mass for it to be dissipated. A typical 3U or 6U off-the-shelf, embeddable SBC dissipates between 35 and 75 W that, when combined as a subsystem with its I/O and power supplies, might easily dissipate more than 100 W. The introduction of low-power processors such as the Intel Atom can potentially reduce this power dissipation by a factor of three, while still offering performance equivalent to a Celeron or Pentium M.
Introduced in 2008, Intel’s low-power Atom, with its x86 code compatibility and integrated graphics controller, fueled a generation of netbooks and portable devices. To save power, Atom’s processing core utilizes a simplified architecture and extensive power management of unused resources. Complex multi-operand x86 instructions are converted to multiple micro operations for a “RISC-like” execution unit. The resultant simplification does not support preemptive or out-of-order processing, but does support multithreading, having two logical processors.
Codenamed Menlow, the original Atom platform can be used with a variety of existing I/O controllers connected via its Front Side Bus (FSB) to achieve the specific functionality needed. This flexibility allows the user to trade off overall power for cost or functionality. The new Queens Bay platform, recently announced at the Intel Developer Forum (IDF), extends the Atom processor even further as a System-on-Chip (SoC) using a 45 nm process, to include higher-performance graphics, a DDR2 memory controller, flash, and four PCI Express x1 interfaces. This device, the E6xx, dispenses with the FSB, instead using one of the PCI Express interfaces for direct connection of peripheral devices through an I/O controller hub providing CANbus, GbE, USB, and SATA. The Queens Bay offers greater processor performance and functionality than Menlow plus lower power, typically from 2.7 to 3.9 W when clocked at up to 1.6 GHz, to reduce the overall dissipation of an embeddable 3U Atom-based SBC to less than 10 W.
3U form factor
While many open architecture small form factors such as EBX, Mini-ITX, PC/104-Plus, or PC/104-Express are readily available for commercial applications, none rival the established position of 3U for rugged applications. CompactPCI and VPX are ideal choices with COTS vendors offering both. The ACR301 from GE Intelligent Platforms (Figure 1) uses the latest E6xx processor platform to provide a very low-power, entry-level SBC in the 3U CompactPCI form factor. The ACR301’s low power and performance potential extend the range of computing technologies for critical 3U-based applications. It also offers many existing users a power saving, plug-in replacement.
Figure 1: The ACR301 Atom-based SBC from GE Intelligent Platforms
(Click graphic to zoom by 1.9x)
Critical applications for low-power computing
Meanwhile, a very large class of man-wearable and portable military applications exists, ranging from personal sensors and radios to netbooks and smartphones, set to benefit from the advances in low-power processors. But these are unlikely to adopt an open architecture form factor such as 3U. These will be wholly custom designed. However, many other application spaces are available. Mission avionics applications on platforms such as helicopters or combat aircraft where weight is always a critical parameter are possibly the most SWaP-sensitive military applications utilizing off-the-shelf, embedded computing modules. Similarly, for an Unmanned Aerial Vehicle (UAV) the avionics, mission system, and sensor payload weights are critical to achieve the desired performance and endurance. Robotic Unmanned Ground Vehicles (UGVs) and scout/surveillance vehicles are complementary low-power applications on the ground. UGVs are typically battery powered and operated wirelessly or remotely via an umbilical. Scout/surveillance vehicles, which can be manned or unmanned, are used for covert surveillance operations requiring long endurance, a low infrared signature, and a passive multisensor suite such as radar, signals, organic material, audio, or LF sensing. These are all required to operate from limited battery power for extended periods.
Alternate I/O hubs
The Atom is a prime example of military embedded computing leveraging expensively developed technology from mass commercial markets. The Queens Bay platform offers CANbus, intended for future automotive “infotainment” systems but equally applicable to a military vetronics system’s driver or commander’s interface. The new E6xx Atom is the basis for a family of processing platforms teamed with application-specific I/O hubs. For example, Intel’s new MP20 platform controller hub includes network security, encryption, and extensive audio processing capability intended for 3G handhelds and smartphones. Such hub combinations offer many new possibilities for further integration of embedded vetronic and avionic capabilities in the future network-enabled battlefield.
To learn more, e-mail Duncan at [email protected].