3 ms·
> half-speed for whatever reason IMHO the reason actually does matter. Utilization should be relative to the maximum frequency the CPU could be running the sa
by dataflow 5y ago
> half-speed for whatever reason
IMHO the reason actually does matter.
Utilization should be relative to the maximum frequency the CPU could be running the same instructions at. If the CPU is throttling to save power, then it could be running the same instructions at a higher frequency, so utilization should be relative to the higher one. If it's throttling to lower the temperature, then it can't be running the same instructions at a higher frequency, so it's already maxed out at 100%.
- nightpool 5y agothat doesn't solve the "relative measures make the graph useless" problem though, does it?
- dataflow 5y agoHm I felt it does, but I might've missed some situation. Why do you feel it doesn't? Could you describe a scenario where it'd be misleading?
- nomel 5y ago> If it's throttling to lower the temperature… This gives the ability to go over 100% before thermals equalize, since max power would follow a Newton cooling curve.
- dataflow 5y agoI don't follow. Whatever frequency the CPU is currently running at is a lower bound on the maximum frequency it could be running at, so it shouldn't exceed 100%?
- nomel 5y agoBut the thermals of the system means it can, for short periods of time, run much faster than long periods of time. I don't think a constantly changing 100%, that changes with temperature, is very useful. I would be more interested in whatever the sustainable 100% is, for normal room temperature.
- gruez 5y ago>Utilization should be relative to the maximum frequency the CPU could be running the same instructions at How do you define "maximum frequency"? For desktops it's relatively easy to define since they usually have good cooling and power delivery that they can always hit the top frequency, but for laptops this often doesn't apply. It might be only able to sustain top frequency for less than a minute before thermal throttling kicks in.
- dataflow 5y agoWhatever frequency it could execute the next cycle at, assuming there was no desire to minimize power usage. It's a transient measure, not a steady-state measure.
- gruez 5y agoThis will cause the system to vastly under-report % values during periods of low load, because the processor thinks it can run at a higher frequency than it can actually achieve/sustain. This is most notable on laptop processors. If I enable "high performance" mode on windows, it would cause the processor to run at its max possible frequency, around 4.1 GHz (which is near the theoretical max turbo frequency) when there's little to no load. However, when there's actual load (eg. 1 core fully loaded), the frequency would drop to around 3.5 GHz. It would get worse as more cores get loaded, all dropping all the way down to 2.3ghz.