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XPS 15 9560 POWER throttles (no thermal throttling)

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Is it normal that when both cpu and discrete gpu of this laptop are 100% used (not benchmarking, just normal usage of software that needs to) there is some kind of POWER throttling on the cpu?

Power Limit 1 goes from 45w to 20w then back to 45 for about 10 minutes, then goes down to 15w and stays there for an undefined amount of time (even if temps are low at about 75 degrees)


(tested on AC)

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RE: XPS 15 9560 POWER throttles (no thermal throttling)

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It is not easy to tell if the laptop is performing reasonably well. CPU temperatures above 90 degC are not normal, indicate a cooling problem, like dust-clogged fins or another heatsink problem. Unfortunately, XPS 15 often benefit substantially from CPU&GPU repasting. Many user photos of heatsink dismounting show too much remaining thermal paste on the dye/sink, indicating that the gap was too thick, sometimes uneven due to misalignment.

Unfortunately, power limit throttling is normal for XPS 15, even with a well-attached heatsink, because the cooling capacity of the heatsink is inadequate for the high-spec CPU and GPU. In particular, the voltage-regulator area is not cooled actively and overheats after sustained combined CPU+GPU load, for instance in certain games and GPU-intensive programs.

I find it very unfortunate that the nominal long-term cooling capacity is not declared in the specifications, because users tend to expect that a laptop would be able to make use of the specced components without restrictions.

I find it even more unfortunate that the power limit throttling (presumably implemented with Intel DPTF) kicks in instantly, causing a sudden rapid drop of performance, rather than smoothly reaching a thermally sustainable performance within the thermal constraints.

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RE: XPS 15 9560 POWER throttles (no thermal throttling)

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Hi lugiank,

Thanks for posting.

Yes, it is normal for the power to throttle under normal usage of software.  From the research I found that programs such as Google Chrome because it is multi-threaded and uses hardware acceleration.  If you need additional data processing speed while the throttling is going on, you can change the setting to High Performance, then the CPU is allowed to stay at the clock rate necessary to process the queue of data for it, then return to normal.  Once you've finished your project, then return the setting to Balanced.

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RE: XPS 15 9560 POWER throttles (no thermal throttling)

Jump to solution

It is not easy to tell if the laptop is performing reasonably well. CPU temperatures above 90 degC are not normal, indicate a cooling problem, like dust-clogged fins or another heatsink problem. Unfortunately, XPS 15 often benefit substantially from CPU&GPU repasting. Many user photos of heatsink dismounting show too much remaining thermal paste on the dye/sink, indicating that the gap was too thick, sometimes uneven due to misalignment.

Unfortunately, power limit throttling is normal for XPS 15, even with a well-attached heatsink, because the cooling capacity of the heatsink is inadequate for the high-spec CPU and GPU. In particular, the voltage-regulator area is not cooled actively and overheats after sustained combined CPU+GPU load, for instance in certain games and GPU-intensive programs.

I find it very unfortunate that the nominal long-term cooling capacity is not declared in the specifications, because users tend to expect that a laptop would be able to make use of the specced components without restrictions.

I find it even more unfortunate that the power limit throttling (presumably implemented with Intel DPTF) kicks in instantly, causing a sudden rapid drop of performance, rather than smoothly reaching a thermally sustainable performance within the thermal constraints.

View solution in original post