AMD Knocks Intel on Power

By John G. Spooner  |  Posted 2005-08-25

AMD Knocks Intel on Power

SAN FRANCISCO—AMD is fighting the power.

Even with Intel Corp.s new focus on delivering higher processor performance per watt of energy, unveiled here at its fall Intel Developer Forum, Advanced Micro Devices Inc. maintains that its Opteron server chips consume less juice than its rival Intels Xeon server chips, either available now or coming in the near future.

AMD executives camped out at atop the Westin St. Francis hotel only a few blocks from Moscone Center West, where the developer forum took place, argued that because Opterons use less power, servers based on them will cost businesses less money to run.

Because they use less electricity, Opteron servers also run cooler and thus require less active cooling and can also be fit more tightly together in server racks, reducing the amount of infrastructure required to run them, an AMD executive said.

"Weve got the best performance-per-watt story today," said Brent Kirby, product marketing manager for Opteron, in an interview with Ziff Davis Internet.

The difference comes down to the companies design philosophies.

Until now, Intel has focused largely on processor speed.

Chips that run faster tend to use more electricity than those that run at slower clock speeds.

AMDs Opteron runs slower, but can be more efficient in that it gets more work done per clock.

It also incorporates a memory controller, which it says saves on power consumption.

Whereas Intels single-core Xeons run at speeds up to 3.8GHz and are likely to come out at around 3GHz when they hit the market in dual-core configurations later this year, AMDs dual-core Opterons wont reach 2.4GHz until later this quarter.

AMD plans to bump the dual-core version of the chip to 2.4GHz creating the Opteron Dual-Core Model 280 and Dual-Core Model 880 for dual-core processor and multiprocessor servers, respectively, within a short time.

Given that its Opteron, which consumes a maximum of 95 watts, has an integrated memory controller, AMD argues it can measure the chip against Intels Xeon, which consumes a maximum about 110 watts to 130 watts, depending on the exact model being measured, and the part of the Xeons supporting chip set, called the north bridge, which integrates the memory controller.

By AMDs math, a dual-processor Intel Xeon system based on Intels latest Irwindale Xeon chip can consume about 50 watts more power than a dual-processor AMD Opteron system.

A dual processor, single-core Opteron servers twin chips will consume a maximum of 190 watts, while a dual-processor, single-core Intel Irwindale Xeon DP system would include two 120-watt chips, AMD said.

The company also adds the Intel memory controller, which it said public documents show consumes an additional 22 watts. Thus AMDs assessment shows an equivalent Intel machines power consumption as 52 watts higher.

That 52-watt difference, multiplied by 500—for a datacenter with 500 servers in it—adds up to more than a $50,000 higher cost in electricity over year, AMD estimates.

Based on an electrical cost of 10 cents per kilowatt hour, and cooling costs, which it did not break out, AMD says a company would spend $133,152 to operate 500 dual-processor, single-core Opteron systems and $183,610 to operate dual-processor, single-core Intel Irwindale Xeon-based servers.

AMD did not specifically compare a dual-processor, dual-core Opteron systems figures to a dual-processor, dual-core Xeon Paxville processor, as the Intel chip isnt out yet.

Read more here about Intels server and chip developments.

The power consumption of both companies dual-core chips versus their single-core chips is roughly the same, however.

Next Page: Incomplete analysis?

Incomplete Analysis


Intel, for its part, viewed the AMD analysis as incomplete.

An Intel spokesman said that AMDs analysis is a worst-case scenario focusing on maximum power consumption, a state that servers—neither based on Intel chips, nor AMD chips—operate in all the time.

"Every single server workload differs," said Bill Kircos, an Intel spokesman.

Meanwhile, servers processors arent the only parts that consume power. Aside from their chip sets, their fans, power supplies and add-in cards all use electricity as well.

"Each company will talk to you about its maximum wattage," Kircos said. However, "Its rare that things stay that high all the time."

Analysts agreed that AMDs current technology is generally more energy-efficient than Intels existing Xeons.

AMD is likely to continue to enjoy an advantage when the dual-core Paxville Xeon DP and MP chips arrive later this year.

However, while that analysis "works today, tomorrow, theyre going to have an issue," said Roger Kay, president of End Point Technologies Associates Inc. Kay was referencing Intels plans to introduce lower power server chips in 2006.

Intel on Tuesday said it would build more energy-efficient, dual-core chips called Conroe, Merom and Woodcrest for desktops, notebooks and servers, respectively, and roll them out in 2006.

Click here to read more about Intels plans to aim for greater efficiency.

The chips will be based on new processor architecture that will help them cut their power consumption by as much as 30 watts.

That means power consumption on its server chips could drop to around 80 watts, Intel said, a figure that would best the current Opteron.

However, the new Intel chips will not integrate a memory controller, meaning that AMD will continue to gain some power advantage from having built in that part.

Although AMD and now Intel have begun paying attention to server power consumption, an analyst reprimanded both companies for not working to curb their chips hunger sooner.

Instead of focusing on power, they sought to improve speed at the expense of higher power consumption, said Jim McGregor, editor of the Microprocessor Report.

"Both companies are way behind in getting to a low power [architecture], because they were so focused on performance and continuing Moores Law" the tenant that processors transistor counts will double, increasing performance, every two years, McGregor said.

Thus "2007 is going to be interesting. Both companies are working on machine changes to their architecture."

Indeed, "The big point here is that its a good thing if our competitor and the industry are all on the same page and looking at energy efficiency," Kircos said.

Analysts believe that Intel will begin integrating a memory controller into its server chips starting in 2007, when it rolls out Whitefield, a quad-core successor to Woodcrest, the dual-core chip due in the second half of 2006.

McGregor said he believes AMD is also working on a low-power processor architecture.

AMD has been mum on its architectural plans.

Its next step is to update the Opteron memory controller to support the DDR-2 specification for faster memory and to add virtualization and security technologies to the chip.

It will roll all of those out in the first half of 2006, Kirby said.

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