I was wondering, if you could go into an application and replace one energy hog, what would it be? It’d have to be something used a lot and in high volumes. Today’s embedded apps like video processing are using more and more data. Let’s reach into the bit bucket for a minute and look at two areas of developments that could help.

Getting flashy

We know that the largest consumers of power have shifted from being industrial facilities to data centers. And as embedded applications take on more and more data, the line between a data center and an embedded computer tied to a big storage system is blurring.

Arguments over the cost, reliability, and performance of flash-based Solid-State Drives (SSDs) versus conventional hard drive technology are well understood. Enter a new parameter to think about: power consumption. Hard drives are effective, using several power management techniques such as spin-down and others, and they still offer larger capacities. But SSDs are closing the gap.

Take the new Pliant Technology Lightning Enterprise Flash Drives, for instance. An apples-to-apples power comparison is difficult because we’d have to take capacity and drive counts into consideration, but a drive with idle power consumption of 3.9 W and typical power of 5.9 W (2.5") or 7.9 W (3.5") is good even compared to cutting-edge hard drives. Available in both 2.5" and 3.5" form factors, these are enterprise-quality drives with 2M hour MTBF, read rates of more than 420 MBps, and write rates of more than 220 MBps. These drives also offer features like a cacheless design to protect against power interruptions and end-to-end data protection like extended ECC.

Again, designers should to take into account the latest hard drive technology with capacity and advanced power management features, yet it is clear that SSDs are becoming a contender for many storage applications using volumes of drives in arrays.

Rethinking the memory

Along those same lines, DRAM presents the same issue; it needs to be fast and offer high capacity. However, people are starting to take a harder look at power consumption. Savings realized from a more efficient multicore processor can be completely offset in power consumed from a bank of high-performance but energy-hogging DRAMs.

There’s a new DRAM idea to help with both performance and power consumption. At Intel Developers Forum this month, Rambus and Kingston Technology are showing off a new DDR3-based threaded module for multicore processors. This new technology partitions modules into multiple independent channels that share a common command/address port. Threaded modules can support 64-byte transfers at full bus utilization, offering an efficiency gain of 50 percent over current DDR3 modules. Also, the DRAM devices are activated only half as often, which Rambus says drops power consumption by 20 percent.

Other companies are continuing to address DRAM power consumption with various approaches. Innovative Silicon, Toshiba, and others are exploring capacitorless designs, which scale to small geometries well and can reduce power while keeping performance high. IBM is working on scheduling and throttling to get beyond simple idling and delay writes without sacrificing more than a couple percentage points of performance.

While these and other sophisticated power management methods for DRAM are still conceptual, the winners will likely start showing up in products soon, and when they do, they’ll give designers a choice to get power out of DRAM subsystems.

Editor’s note: Lead image courtesy of Sun Microsystems, Inc.