This Monday startup SeaMicro launched a server that packs 512 Intel® Atom™ processors in a 10U chassis. According to the company, this remarkable piece of hardware can deliver the same performance as conventional server while using only 1/4 the power and space. I have to say that I am thoroughly impressed by this server. It really shows the potential of the Intel Atom, and it demonstrates the value of questioning your assumptions—lessons that directly apply to embedded systems.
SeaMicro’s new server—known as the SM1000—is a leading example of a new class of servers built around mobile processors. This new class of servers is being developed in response to Web 2.0 workloads and the rise of the Internet of Things. Traditional server workloads are characterized by large, complex workloads like database processing. For these workloads, conventional servers based on Intel® Xeon® processors are the way to go. However, Web 2.0 applications and Internet-connected devices are creating a new type of workload—one with huge numbers of small tasks. For this new workload, SeaMicro says the Intel Atom can provide major advantages in terms of performance per watt.
But it turns out that the processor is only one part of the equation. According to SeaMicro, the CPU consumes only 1/3 of the total power in a conventional server. Most of the power is burned by motherboard components such as storage and network controllers. Even if you could cut the CPU power to zero, you’d still burn a lot of juice. SeaMicro addressed this quandary by creating its own ASICs to get rid of these power-hungry components. In fact, the SeaMicro’s server boards have just three components: the Intel Atom chipset, DRAM, and the SeaMicro ASIC (see Figure 1).
Figure 1. SeaMicro fit eight servers onto a 5 x 11” board by eliminating all components except the Intel Atom chipset, the SeaMicro ASIC, and DRAM (which is on the reverse side of the board).
SeaMicro has also taken a novel approach with its load balancer. Unlike a standard load balancer, which attempts to spread the workload evenly across all processors, SeaMicro’s balancer attempts to keep each processor either idle or fully loaded. SeaMicro took this approach because the Intel Atom Z530 processors in its server support the deep-sleep C6 mode, where they burn a measly 80mW. Thus, idling as many processors as possible lets the server save a considerable amount of power.
So what can embedded system developers learn from all this? For starters, you should examine your assumptions. For example, I’ve observed a widespread belief that if power is your priority, ARM is the best choice. SeaMicro’s experience shows that this is far from a solid assumption. Before selecting the Intel Atom, SeaMicro tested a number of ARM-based processors. In the end, SeaMicro found that the Intel Atom offered the best performance per watt.
When challenging your own assumptions, make sure you are thinking at the system level. Looking at the performance, price, and power of the processor is a good place to start, but it doesn’t tell you everything. Again, look at the example of SeaMicro, where the biggest power savings came from changing the motherboard components.
Another lesson we can learn from SeaMicro is the value of combining an Intel Atom with custom logic. You probably won’t want to spin an ASIC, but you can always combine the Intel Atom with an FPGA. One option here is the Men Micro F11S, a 3U CompactPCI single-board computer (SBC) that combines an Intel Atom Z5xx with an FPGA for user-defined I/O (see Figure 2).
Figure 2. The Men Micro F11S CompactPCI module includes an FPGA for user-defined rear I/O.
Another promising option is Avnet’s new Xilinx Spartan-6 FPGA PCIe I/O Reference Design. This kit combines Kontron’s nanoETXexpress-SP module and nanoETXexpress evalation board with the Xilinx Spartan-6 SP605 development board shown in Figure 3.
Figure 3. Avnet’s new Intel Atom+FPGA kit includes this feature-rich Xilinx Spartan-6 SP605 FPGA board.
National Instruments also offers a number of solutions that help you build Intel Atom+FPGA combos. For an example, see the article How to Integrate NI Single Board RIO with an Intel Atom based Computer on Module (COM) SBC.
Embedded developers can also learn a lesson from SeaMicro’s focus on total cost of ownership (TCO). SeaMicro’s main selling point it can reduce ownership costs—particularly the cost of power. This is a message that IT customers understand well—Gartner Research popularized the concept of TCO way back in 1987, and it has been a hot topic for IT professionals ever since. In the embedded world, however, I rarely see discussion of ownership costs. This suggests an opening. If your competitors are not thinking about ownership costs, you can get a competitive advantage by offering a solution with lower power, better reliability, easier maintenance, etc. (See my recent blog on cutting TCO in digital signage for one example.) So how will you take advantage of this opening?
Kontron is a Premier member of the Intel® Embedded Alliance. National Instruments is an Associate member of the Alliance. Xilinx and Men Micro are Affiliate members of the Alliance.
Roving Reporter (Intel Contractor)
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