Power management
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (June 2008) |
Power management is a feature of some electrical appliances, especially
Motivations
PC power management for computer systems is desired for many reasons, particularly:
- Reduce overall energy consumption
- Prolong battery life for portable and embedded systems
- Reduce cooling requirements
- Reduce noise
- Reduce operating costs for energy and cooling
Lower power consumption also means lower
Processor level techniques
The power management for microprocessors can be done over the whole processor, or in specific components, such as cache memory and main memory.
With dynamic voltage scaling and dynamic frequency scaling, the CPU core voltage, clock rate, or both, can be altered to decrease power consumption at the price of potentially lower performance. This is sometimes done in real time to optimize the power-performance tradeoff.
Examples:
- AMD Cool'n'Quiet
- AMD PowerNow![1]
- IBM EnergyScale[2]
- Intel SpeedStep
- Transmeta LongRun and LongRun2
- VIA LongHaul (PowerSaver)
Additionally, processors can selectively power off internal circuitry (power gating). For example:
- Newer Intel Core processors support ultra-fine power control over the functional units within the processors.
- AMD CoolCore technology get more efficient performance by dynamically activating or turning off parts of the processor.[3]
Heterogeneous computing
Operating system level: hibernation
When a
In GPUs
Graphics processing unit (
DVFS techniques
Experiments show that conventional processor DVFS policy can achieve power reduction of
Power gating techniques
Much research has been done on the dynamic power reduction with the use of DVFS techniques. However, as technology continues to shrink, leakage power will become a dominant factor.[9] Power gating is a commonly used circuit technique to remove leakage by turning off the supply voltage of unused circuits. Power gating incurs energy overhead; therefore, unused circuits need to remain idle long enough to compensate this overheads. A novel micro-architectural technique[10] for run-time power-gating caches of GPUs saves leakage energy. Based on experiments on 16 different GPU workloads, the average energy savings achieved by the proposed technique is 54%. Shaders are the most power hungry component of a GPU, a predictive shader shut down power gating technique[11] achieves up to 46% leakage reduction on shader processors. The Predictive Shader Shutdown technique exploits workload variation across frames to eliminate leakage in shader clusters. Another technique called Deferred Geometry Pipeline seeks to minimize leakage in
See also
- 80 Plus
- Advanced power management(APM)
- Advanced Configuration and Power Interface(ACPI)
- BatteryMAX (idle detection)
- Constant Awake Mode
- CPU power dissipation
- Dynamic frequency scaling
- Dynamic voltage scaling
- Energy Star
- Energy storage as a service (ESaaS)
- Green computing
- Low-power electronics
- pmset
- PowerTOP – diagnostic tool
- Run-time estimation of system and sub-system level power consumption
- Sleep Proxy Service
- Standby power
- The Green Grid
- Thermal design power
- VESA Display Power Management Signaling (DPMS)
References
- ^ "AMD PowerNow! Technology with optimized power management". AMD. Retrieved 2009-04-23.
- ^ "IBM EnergyScale for POWER6 Processor-Based Systems". IBM. Retrieved 2009-04-23.
- ^ "AMD Cool'n'Quiet Technology Overview". AMD. Retrieved 2009-04-23.
- ^ "What is GPU computing". Nvidia.
- ^ "Dynamic voltage and frequency scaling framework for low-power embedded GPUs", Daecheol You et al., Electronics Letters (Volume:48, Issue: 21 ), 2012.
- ^ "Effects of Dynamic Voltage and Frequency Scaling on a K20 GPU", Rong Ge et al., 42nd International Conference on Parallel Processing Pages 826-833, 2013.
- ^ "GreenGPU: A Holistic Approach to Energy Efficiency in GPU-CPU Heterogeneous Architectures", Kai Ma et al., 41st International Conference on Parallel Processing Pages 48-57, 2012.
- ^ "Power and performance analysis of GPU-accelerated systems", Yuki Abe et al., USENIX conference on Power-Aware Computing and Systems Pages 10-10, 2012.
- ^ "Design challenges of technology scaling", Borkar, S., IEEE Micro (Volume:19, Issue: 4 ), 1999.
- ^ "Run-time power-gating in caches of GPUs for leakage energy savings", Yue Wang et al., Design, Automation & Test in Europe Conference & Exhibition (DATE), 2012
- ^ "A Predictive Shutdown Technique for GPU Shader Processors", Po-Han Wang et al., Computer Architecture Letters (Volume: 8, Issue: 1 ), 2009
- ^ "Power gating strategies on GPUs", Po-Han Wang et al., ACM Transactions on Architecture and Code Optimization (TACO) Volume 8 Issue 3, 2011