3 ms·

Another factor (also mentioned in the article) is dynamic frequency scaling. Is a core at 100% when it's running at it's running 'flat-out' at its nominal frequ

by bpye 3y ago

Another factor (also mentioned in the article) is dynamic frequency scaling. Is a core at 100% when it's running at it's running 'flat-out' at its nominal frequency or when it has boosted? The boost clock generally depends on thermals, silicon quality and maybe time - so in that case what do you make 100%? If you go for nominal being 100% then sometimes you're going to be at say 120%.

mjevans 3y ago
The most obvious answer: 100% is what the manufacturer claims it capable of handling continuously under the worst supported conditions. The more difficult answer/question is how to communicate that 'full use' value as well as the current use (possibly greater than full) to software which calculates a usage estimate based on various already existing interfaces. Or if yet another interface (standard, if thinking about that XKCD comic) is needed.
- Dalewyn 3y ago
  I prefer the NASA approach: 100% is whatever as defined in the spec sheet, and any improvements above that are measured in percentages above 100. As an example, the SSME was nominally operated at 104.5%, and the newer expendable RS-25Es nominally operate at 111%.[1] So basically: 100% is the CPU running at base frequency, and anything higher (eg: turboing/boosting, overclocking) should result in even higher percentages above 100. This would be a lot more meaningful than whatever "100% CPU load" means today. [1]: https://en.wikipedia.org/wiki/RS-25#Engine_throttle/output https://en.wikipedia.org/wiki/RS-25#Engine_throttle/output
  - mjevans 3y ago
    That's mostly what I stated, though with adjustable frequency products like CPUs and GPUs the question of 'what is the base frequency' is also a question. That's why I carefully phrased around manufacturer's claimed continuous operation in the worst environment supported spec. (Though implicitly with adequate cooling operating, not obviously broken cases like a CPU with it's heat sink shaken off.)

by bpye 3y ago

mjevans 3y ago

The most obvious answer: 100% is what the manufacturer claims it capable of handling continuously under the worst supported conditions. The more difficult answer/question is how to communicate that 'full use' value as well as the current use (possibly greater than full) to software which calculates a usage estimate based on various already existing interfaces. Or if yet another interface (standard, if thinking about that XKCD comic) is needed.

Dalewyn 3y ago
I prefer the NASA approach: 100% is whatever as defined in the spec sheet, and any improvements above that are measured in percentages above 100. As an example, the SSME was nominally operated at 104.5%, and the newer expendable RS-25Es nominally operate at 111%.[1] So basically: 100% is the CPU running at base frequency, and anything higher (eg: turboing/boosting, overclocking) should result in even higher percentages above 100. This would be a lot more meaningful than whatever "100% CPU load" means today. [1]: https://en.wikipedia.org/wiki/RS-25#Engine_throttle/output https://en.wikipedia.org/wiki/RS-25#Engine_throttle/output
- mjevans 3y ago
  That's mostly what I stated, though with adjustable frequency products like CPUs and GPUs the question of 'what is the base frequency' is also a question. That's why I carefully phrased around manufacturer's claimed continuous operation in the worst environment supported spec. (Though implicitly with adequate cooling operating, not obviously broken cases like a CPU with it's heat sink shaken off.)