Sustainable IT | Ted Samson » TAG: Chips

November 29, 2007 | Comments: (0)

Emerson delivers free Energy Logic blueprint for building a power-efficient datacenter

TAGS: Chips, Cooling, Emerson Network Power, Energy conservation, Hardware, Power consumption, Power supplies, Processors, Server virtualization

How-to guides are downright handy for tackling daunting projects, such as deploying a new BPM (business process management) solution or building a birdhouse (one of those really fancy ones with indoor plumbing).

One of the most daunting tasks that companies face today is figuring out how to wring greater energy efficiency out of their datacenters. Certainly, many vendors are ready to step up and demonstrate where their respective products fit into the power-saving puzzle. But there's something to be said for a vendor-neutral blueprint to plan the overall task.

That all is a wordy lead-in to pointing you to a new report -- available as a free download -- released today by Emerson Network Power. It's titled "Energy Logic: Reducing Data Center Energy Consumption by Creating Savings that Cascade Across Systems," and it's an impressive piece of work, outlining ten interrelated technology strategies that comprise a holistic approach to improving datacenter energy efficiency by as much as 50 percent, according to the company. And as I noted, it's free.

For a little background, Emerson has coined the term "Energy Logic" in this report, a strategy which, according to the company, "centers on 'the cascade effect' by which one watt saved at the processor level can save an average total of 2.84 watts in energy consumption."

The report starts at the server component level, outlining the benefits of low-power processors. "Independent research studies show these lower-power processors deliver the same performance as higher power models," the report says. "In the 5,000-square-foot datacenter modeled for this paper, low-power processors create a 10 percent reduction in overall datacenter power consumption."

Next up: power supplies. The report notes that most power supplies found in servers are working at around 72 percent effiency -- yet "best-in-class power supplies are available today that deliver efficiency of 90 percent. Use of these power supplies reduces power draw within the data center by 124 kW or 11 percent of the 1127 kW total," the report says.

From there, the report suggests that datacenter operators look at power-management software. Despite the fact that processors have built-in power-management features, they end up disabled for fear of crippling response time. Yet "in idle mode, most servers consume between 70 and 85 percent of full operational power."

The Emerson Energy Logic report suggests that admins reconsider how they use power-management features. In the 5,000 square foot datacenter model, the report says that using power-management features can reduce peak power draw from 80 percent to 45 percent, saving "an additional 86 kW or eight percent of the unoptimized datacenter load."

Blade servers have a role to play in the energy-efficient datacenter, according to the Emerson report. "Blade servers consume about 10 percent less power than equivalent rack-mount servers because multiple servers share common power supplies, cooling fans and other components. ... More importantly, blades facilitate the move to a high-density data center architecture, which can significantly reduce energy consumption."

Moving on, Emerson's Energy Logic strategy highlights server virtualization. In the 5,000 square foot model, "assuming 25 percent of servers are virtualized with eight non-virtualized physical servers being replaced by one virtualized physical server, ... virtualization provides an incremental eight percent reduction in total datacenter power," according to the report.

No. 6 on Emerson's energy-efficiency menu for datacenters: best cooling practices. That includes "sealing gaps in floors, using blanking panels in open spaces in racks, and avoiding mixing of hot and cold air." This is low-hanging fruit that requires no additional technology investment but can result in a five percent efficiency boost, based, again, on the 5,000 square foot datacenter model.

415V AC power distribution is the next strategy component in Emerson's Energy Logic scheme. The short of it is, most UPS systems are rather inefficient, as they convert incoming power to DC and then back to AC within the UPS. "In most datacenters, the UPS provides power at 480V, which is then stepped down via a transformer, with accompanying losses, to 208V in the power distribution system," according to the report. "These stepdown losses can be eliminated by converting UPS output power to 415V." The result: "an incremental two percent reduction in facility energy use" in the 5,000 square foot model.

Cooling reappears in the report next, specifically variable capacity cooling. "Typically, CRAC [computer room air conditioners] fans run at a constant speed and deliver a constant volume of air flow. Converting these fans to variable frequency drive fans allows fan speed and power draw to be reduced as load decreases," the report says. Emerson specifically cites digital scroll compressors here, which "allow the capacity of room air conditioners to be matched exactly to room conditions without turning compressors on and off."

The payoff: "A 20 percent reduction in fan speed provides almost 50 percent savings in fan-power consumption."

Ninth in the Emerson Energy Logic lineup is, lo, another cooling strategy: high-density supplemental cooling. Datacenter operators are cramming more machines into their facility, and CRAC systems alone can't handle the extra heat. "Supplemental cooling units are mounted above or alongside equipment racks, and pull hot air directly from the hot aisle and deliver cold air to the cold aisle," the report explains. These units can reduce cooling costs by 30 percent, Emerson reports.

Last but not least, there's monitoring and optimization. With varying types of hardware spread out around the datacenter, cooling can prove inefficient. "Cooling control systems can monitor conditions across the datacenter and coordinate the activities of multiple units to prevent conflicts and increase teamwork," the report says. "In the model, an incremental saving of one percent is achieved as a result of system-level monitoring and control."

There's plenty more information to be gleaned from Emerson's 21-page Energy Logic report, along with helpful charts and diagrams to help datacenter operators as they venture toward a greener, more sustainable facility.

Did I mention the report is available as a free download? Get it right here.

Ted Samson is a senior analyst at InfoWorld and author of the Sustainable IT blog, tracking trends toward greener, more energy-efficient IT. Subscribe to his free Green Tech newsletter here.

Posted by Ted Samson on November 29, 2007 10:02 AM

August 30, 2007 | Comments: (0)

Power-efficiency test reveals respective strengths of AMD and Intel

TAGS: AMD, Chips, Intel

In its latest round of power-efficiency tests pitting the AMD Opteron against the Intel Xeon, independent consulting firm Neal Nelson and Associates found that AMD's offering outperformed Intel's in 36 of 57 cases.

The results are by no means cut and dry. While the AMD appears to once again have an edge in terms of raw power effienecy, factors such as memory size, transaction type, and transcation loads made for notable and interesting differentiators.

Nelson performed this gauntlet of tests on servers -- one equipped with the Opteron 2222 and the other with the Xeon (Woodcrest) 5160 -- configured with two, four, six, and eight gigabytes of main memory at various transaction-processing load levels.

Overall, Nelson found that for certain configurations and at certain load levels, the Intel Xeon based server was 2.4 to 11.7 percent more power efficient while in other cases the AMD Opteron based server was 9.2 to 23.1 percent more power efficient.

Memory once again proved an important variable. In general, larger main memory sizes resulted in higher transaction throughput and higher power efficiency. Further, in cases where Intel outperformed AMD in power efficiency, the servers were configured with smaller larger memory sizes. "There was a visible trend that as the memory size increased that there was an increasing shift of power-efficiency toward the Opteron," Nelson notes the white paper outlining his testing.

Importantly, Nelson discovered differences in power-performance depending on what type of work the servers were doing. At the maximum throughput, based on transactions per watt hour, the Intel system delivered better power-efficiency by 5.0 to 5.5 percent for calculation intensive workloads. For disk I/O intensive workloads, AMD delivered better power efficiency by 18.4 to 18.6 percent.

In addition, when the systems were idle and waiting for transactions to process, the AMD server was 30.4 to 53.1 percent more power efficient.

He put the machines through two different tests. One employed the Neal Nelson Transaction Benchmark, in which simulated Web clients present transaction requests to the server. As soon as the server responds to a request, the client submits a new request.

In the second test, employing the Neal Nelson Power-Efficiency Benchmark, he presented the servers with a set number of transactions, then measured the power expended for each transaction arrival rate.

For the loads, he simulated over-the-Web credit card transactions on the servers from RTE (Remote Terminal Emulator) nodes to the machines, which were running Apache2.

You can read the white paper outlining the testing and results here on the Neal Nelson and Associates Web site.

Posted by Ted Samson on August 30, 2007 05:24 PM

August 14, 2007 | Comments: (0)

A mighty ionic wind could revolutionize chip-cooling

TAGS: Chips, Cooling, Future technology, Intel

Researchers at Purdue University have demonstrated a new technology that employs "ionic wind engines" to cool chips as much as five times more effectively than other experimental cooling approaches, the institution reports.

In their testing, researchers found that the technology reduced heating from about 140 degrees Fahrenheit to about 95. This kind of cooling technology could help hardware makers develop thinner, more powerful laptops, according to Purdue. (I imagine it could also show up in server hardware.)

"In computers and electronics, power equals heat, so we need to find ways to manage the heat generated in more powerful laptops and handheld computers," said Timothy Fisher, associate professor of mechanical engineering at Purdue.

According to Purdue, the cooling technology could appear in computers in the next three years -- if researchers are able to reduce the size of components within the device from the scale of millimeters to microns, or millionths of a meter. They'll also have to figure out how to make the system sufficiently rugged.

"As things get smaller, they get more delicate, so we need to strengthen all the elements. And we believe we can achieve this goal in a year or so," said Suresh Garimella, a professor of mechanical engineering at Purdue.

Down the road, it could also show up in portable devices such as cell phones.

The technology uses tiny "ionic wind engines" to achieve its supercool chilling effect. Here's how Purdue explains it: The device contains a positively charged wire, or anode, and negatively charged electrodes, called cathodes. When voltage passes through the device, the negatively charged electrodes discharge electrons toward the positively charged anode. Along the way, the electrons collide with air molecules, producing positively charged ions, which were then attracted back toward the negatively charged electrodes. This creates the "ionic wind," which increases the airflow on the surface of the experimental chip.

The research, funded by Intel, was conducted and documented in a paper by Fisher, Garimella, mechanical engineering doctoral student David Go, and Intel research engineer Rajiv Mongia. Specifics about the research will appear in the Journal of Applied Physics, tentatively scheduled for the Sept. 1 issue.

Posted by Ted Samson on August 14, 2007 11:44 AM