| Uploader: | Maumuro |
| Date Added: | 12 March 2014 |
| File Size: | 34.10 Mb |
| Operating Systems: | Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X |
| Downloads: | 79093 |
| Price: | Free* [*Free Regsitration Required] |
If power cap is set to 45 watts no DVFS and turbo boost is onthe observed frequency is more or less 1. Log in to post comments.
RAPL power capping: how does it work
I read through the two sections in the manual, still I'm not very clear what is the difference between duty cycle modulation and clock cycle modulation? There are several use cases for such technologies: Also there are other technologies available, for power capping various devices.
I seem to recall one case with severe thermal throttling that was running very slowly as if duty cycle modulation was being employedbut I never saw any changes to the corresponding MSRs. Power capping must have done differently among these two kinds of applications. Add class driver PowerCap: Hello, i'm looking at performance variations of my application under a range of power caps. Leave a Comment Please sign in to add a comment.
If the power limitation is low, it manipulates clock duty cycles. Each device can report its power consumption. Changes in retired instruction rate may indicate hardware clock cycle modulation.
With a high power cap, the performance is reasonable. For more complete information about compiler optimizations, see our Optimization Notice.
Power Capping Framework and RAPL Driver
If each device can be constrained to some power, extra power can redistributed to other devices, which needs additional performance. One possible interpretation is that the MSRs show software-controlled duty-cycle modulation, but may not show hardware-initiated duty-cycle modulation. My questions is how RAPL caps the power. I often find it difficult to figure out which parts of Chapter 14 of Volume 3 of the Intel Architectures SW Developer's Manual actually apply to my systems.
Power Capping framework is an effort to have a uniform interface available to Linux drivers, which will enable - A uniform sysfs interface for all devices which can offer power capping - A common API for drivers, which will avoid code duplication and easy implementation of client drivers. It is easy enough to monitor the actual unhalted processor cycles to determine the average frequency.
Skip to main content. Someone told me, if the power cap is high, it does DVFS.
Setting power limits on the devices allows oower to guard against platform reaching max system power level. Article Overview With the evolution of technologies, which enables power monitoring and limiting, more and more devices are able to constrain their power consumption under certain limits. Setting power cap directly to 75 watts no DVFS and turbo boost is onthe frequency is 1.
At least some processors will support frequencies below the "maximum efficiency" frequency, but I don't know if the Power Control Unit will use these or switch to duty cycle modulation Section Where can cappinb find official information? I checked duty cycling and clock modulation.
Added to drivers cappimg bitops: While staying below a power limit, it allows devices to automatically adjust performance to meet demands - Dynamic control and cappinf Setting DVFS to 1. Depending on your processor, another place to look for DVFS is in the "uncore" clock. With a low power cap, the perfromance is very bad. Fri, 4 Oct Soon it is very likely that other vendors are also adding or considering such implementation.
Comments
Post a Comment