AMD's Ryzen exceeds its '25x20' power efficiency challenge

Jun 28, 2020
AMD's Ryzen exceeds its '25x20' power efficiency challenge


AMD said Thursday that the company has met and even exceeded the "25x20" goal that it set in 2014, in which it challenged itself to improve the energy efficiency of its processors by 25X by 2020.

AMD said the actual proportion was 31.7 times the energy efficiency of its 2014 processor, the AMD "Kaveri" FX-7600P, which was rated at 35 watts TDP. (Thermal design power, or TDP, typically refers to the "worst-case" scenario for thermal power.) AMD compared it to the Ryzen 7 4800H, a 45W part that can be configured down to 35W. 

"In consumer applications on PCs, it's all about the experience, and the efficiency at the end of the day, because we have an environmental load with everything that we do," said Mark Papermaster, AMD's chief technology officer, in an interview with PCWorld. "That was our corporate-level commitment, to orient everything we do, to bring high performance, across the markets we serve, but to do it at a very, very high efficiency."


A finer-grained look at the way AMD has managed power across successive generations, as showed off by AMD fellow Sam Naffziger.

A number of factors contributed to AMD's improvements, which began when the company's mobile power efficiency was "not competitive," Krewell said. Six years ago, the FX-7600P boasted just four cores and four threads, on a 28nm process. AMD has since leapt two additional process nodes, to 7nm. The Ryzen 7 4800H is now an insanely high-performance member of the Ryzen Mobile 4000 family, and an 8-core/16-thread part.

A significant chunk of AMD's power efficiency can probably be traced to AMD's process shifts, but the performance side of the equation has been lifted by AMD's rapid increase in core count, improved "chiplet" design, plus algorithms like Precision Boost 2 and Extended Frequency Range to keep its Ryzen processors in the upper echelons of its boost frequencies as often as possible. Overall, however, more of AMD's 25x20 achievement was enabled by the power side of the equation, Krewell said.

"They've added a lot more fine-grained power management over the years," Krewell said. "Overall, they're just better engineered."

This story was updated at 10:49 AM with additional comments from AMD's Papermaster and Naffziger.