AMD tackles thorny problem of laptop battery life
AMD will improve its chips' power consumption over the next 6 years, hoping for idle battery life in laptops of up to 50 hours
June 20, 2014, 5:25 PM — Advanced Micro Devices is reworking its core PC chip design to be 25 times more energy-efficient over the next six years, possibly resulting in laptop battery life of up to 50 hours on idle time.
So said Sam Naffziger, corporate fellow at AMD, adding that estimated battery life on active use would also be significantly better, although he couldn't quantify that expected improvement.
AMD is trying to sharpen performance-per-watt, with an equal emphasis on power efficiency and performance enhancements. Technological advances like reductions in chip size, restructuring of transistors, new memory technologies, solid-state drives and software improvements will also help AMD in meeting its goals.
In the past six years, AMD has delivered a 10-times improvement in performance-per-watt through its chips. But the company is now taking a fine-grained look at circuitry so inactive parts can be shut down at the microsecond level when not in use.
AMD will achieve the energy-efficient improvements on both its x86 and ARM architecture chips, Naffziger said. The ARM processors, used in most smartphones and tablets, are considered more power-efficient than the x86 chips.
AMD's performance-per-watt improvement estimates over the next six years are based on the joint performance of CPUs and GPUs, which the company integrates on one chip. But much of the overall performance improvement recently has been driven by the GPU.
Manufacturing challenges have also made chips harder to reduce in size, so software and hardware modifications are key to bring more battery life to laptops. "Moore's Law isn't doing us any favors in power efficiency anymore," Naffziger said.
AMD is mainly counting on software improvements that make efficient use of CPUs and GPUs to reach its energy efficiency goals. The company is releasing parallel programming tools that harness the joint computing power of CPUs and GPUs. GPUs could offer 10 times more performance-per-watt in some cases, Naffziger said.
AMD's on-chip improvements include pooling memory resources that all processing units can access. The capability reduces latency and uses fewer system resources, contributing to overall energy efficiency. An early version of the pooled memory implementation is available in Microsoft's Xbox One and Sony's PlayStation 4, and also AMD's own Kaveri chips, released earlier this year.
At the chip level, AMD plans to implement fine-grained power-gating features, shutting and activating processing units at lower levels of circuitry than currently possible. Real-time performance trackers will be used so the right amounts of power are assigned to each active circuit.
"We can dynamically optimize it at the microsecond," Naffziger said.
For graphics, AMD will take power management down to each frame rate to provide just enough power to play video at specific resolutions. Graphics can be power hungry, and the goal is to cut the overhead, Naffziger said.
"There's a lot of opportunity to improve," Naffziger said.
Intel has been putting more voltage regulators on chips to control power consumption. But with chips getting smaller, loading too many voltage regulators may be costly and add complexity to chip design, Naffziger said. AMD will evaluate the number of voltage regulators and their capabilities to hit an optimal point.
