AMD Chips To Offer Power-Capping Technology

Advanced Micro Devices for the past several years has been able to work with some of its largest users to create customised Opteron chips to meet their performance and power needs.

These are some of the larger Internet-type companies, with massive data centres and tens of thousands of servers, who need as much performance as they can get while maintaining high-density and lower-power costs, according to Brent Kerby, senior product marketing manager for servers with AMD.

“A lot of the big cloud guys, the big mega-data-centre types, are focused specifically on meeting the demands of their parallel workloads,” Kerby said in an interview with eWEEK, but declined to name the customers.

Customisation And Chips

AMD engineers have put various controls into the Opteron BIOS over the years that can be manipulated to adjust various parts of the chip to meet specific performance and power demands from customers. This has allowsed the chip maker to create customised Opteron processors for their largest users. Such customisation efforts have been reserved for these large customers that buy thousands or tens of thousands of AMD-powered servers at a time.

However, with the upcoming 16-core Interlagos and eight-core Valencia Opteron chips based on the “Bulldozer” core, AMD is looking to give mainstream customers greater control over the performance and power consumption of their AMD chips, according to Kerby.

With the new Bulldozer-based Opterons, set for release in the third quarter, AMD is introducing TDP Power Cap, which will give enterprises the ability to set the thermal design power (TDP) of their processors, essentially customising their chips to meet power and workload demands. Using various settings in the BIOS, businesses will be able to reduce the overall TDP of the chip but they will not be able to increase it beyond the maximum level set by AMD.

This will help in power consumption and then tweak the frequency of the cores as needed to get the maximum amount of performance allowed under the TDP setting, Kerby said. “While you set the [TDP] cap, you can still operate at a high frequency,” he said.

In addition, businesses can keep the TDP at the level set by AMD, and change the frequencies of the processors to add power, while keeping the overall power use under the TDP.

Bulldozer With Logic

There is also logic built into the Bulldozer architecture, called Application Power Management, that manages the power budget and power resources, including pushing power to specific cores when needed to keep them below the TDP setting, Kerby said.

For high-density, highly bladed data centre environments, such as cloud computing and Web serving, such capabilities can be key in keeping the power consumption down while maximising the performance of the systems, Kerby said.

TDP Power Cap is one of several new features coming in Bulldozer-based chips designed to let enterprises manage the power consumption and performance of their processors better. When combined with other existing and new capabilities in the Opteron chips, customers are given an unprecedented level of flexibility in customising their processors and shaping their data centre environments, according to AMD.

Being able to lower the TDP of the chip can result in an enterprise being able to add more blade systems to a rack, and do so without significantly reducing performance.

That capability is a key difference between the new TDP Power Cap feature and AMD’s existing PowerCap Manager feature, which lets managers cap the power consumption of a processor in its operational state, or p-state, which can help improve energy efficiency but comes with a performance hit as well, John Fruehe, director of product marketing for server, embedded and FireStream products at AMD, said in an interview with eWEEK.

Power Cap For Data Centres

Nathan Brookwood, principal analyst at Insight 64, said AMD’s TDP Power Cap technology could be a benefit for data centre managers looking to squeeze more performance out of their infrastructures while keeping the power consumption down. The technology gives them “the ability to customise their processor and at the same time not sacrifice all the performance”, Brookwood said in an interview with eWEEK.

Whether it will give users reason to choose Opterons over Intel’s Xeons comes down to a key metric, he said.

“Ultimately it will depend on the performance-per-watt in the Bulldozer versus the performance-per-watt in [Intel’s] Westmere and Sandy Bridge, [Xeons],” Brookwood said. “Performance-per-watt is what people are always going to look at.”

Along with TDP Power Cap, AMD in the Bulldozer-based Opterons will introduce an enhanced version of Turbo Core, a technology that was first launched last year in AMD’s Phenom chips and that essentially enables users to push the chip’s base speed up closer to the level of the TDP. The feature enables users to squeeze extra performance out of the chip and gain maximum clock speeds, and will complement TDP Power Cap in the area of customisation, according to AMD.

Advanced Platform Management Link (APML), which allows for remote power management, will also work with TDP Power Cap, according to AMD’s Kerby.

Power Efficiency Core To Opterons

AMD officials have been talking power efficiency since the first Opterons were rolled out almost a decade ago. Over the years, the vendor has added a host of power-management technologies, including PowerCap Manager, PowerNow, Dual Dynamic Power Management and CoolCore.

All these technologies – including TDP Power Cap – will help AMD in its efforts to court the large cloud and Internet businesses, that are trying to cram as much performance into their facilities as possible without ramping up the power consumption, Insight 64’s Brookwood said.

“These days, more and more, it comes down to performance-per-watt,” he said. “In these Internet-scale data centres, where there are thousands or tens of thousands of servers, these guys are extremely sensitive to performance-per-watt. So anything that you can do in this area will go a long way to making them like your product.”

Not only is larger rival Intel also making inroads in driving down power consumption while increasing performance, but mobile chip designer ARM Holdings and many of its partners – including Nvidia, Marvell Technologies and Calxeda – are also looking to move their highly energy-efficient chip designs up into the data centre, for servers aimed at such environments as Web serving and cloud computing.

Tilera, which is rolling out its own low-power, multi-core designs, is another looking at that sector.