CPU throttling happens on many different timescales. That's why Intel processors have multiple power limits (PL1, PL2, PL3, PL4), in addition to current and temperature-based throttling mechanisms. The time constant for PL2 is usually either 28 seconds or 56 seconds. At those timescales, the concern is usually not with power delivery or CPU die temperature but rather with exterior case temperatures that the user may be directly touching.
Based on the reported benchmark performance, it seems very unlikely that temperature-based throttling kicked in, and it's clear that the chip was operating well above 35W for at least a large portion of the benchmark run. So the PL1 and PL2 turbo power limits are the relevant controls at play here.
Yeah yeah, I know. I'm just saying that there's zero chance that throttling is affecting this measurement. The idea that an Intel machine is significantly faster for 2-3 minutes after the start of a benchmark is just silly, that's not the way these things work. Go start a benchmark of your own to see.
Again, the thermodynamic argument is fundamental here. You're saying that a "35W" CPU is "actually" drawing power equivalent to a 125W CPU for exactly the time of a benchmark, which is several minutes. That excess would have nowhere to go! There's no reservoir to store it. (Obviously the cooling system could take it away, but part of your argument is that the cooling system is only good for 35W!).
> The idea that an Intel machine is significantly faster for 2-3 minutes after the start of a benchmark is just silly, that's not the way these things work. Go start a benchmark of your own to see.
I've done so, on many occasions, with actual power meters rather than trusting software power estimates. You really do commonly see a laptop's power consumption drop significantly ~28 seconds into a multithreaded CPU benchmark.
> (Obviously the cooling system could take it away, but part of your argument is that the cooling system is only good for 35W!).
I make no such claim that the cooling system is limited to 35W. I only claim that the default platform power management settings from Intel impose a 35W long-term power limit, unless the system builder has adjusted the defaults to account for whatever form factor and cooling choices they've made.
Perhaps you haven't realized that the turbo power limits will still kick in even if the CPU die temperature is not too hot—because they're not actually a temperature-based control mechanism?
It's a socketed CPU intended for low-power small form factor systems and thus will usually be running with Intel-recommended power limits or lower, for all the same reasons that laptop CPUs are usually running with low power limits. The control mechanisms don't actually function any differently between their laptop and desktop CPUs, they just have different default parameters (the various turbo limits).
The only relevance of the socketed nature of this part is that it is easy to put it in a normal desktop form factor where a big heatsink and possibly tweaked turbo limit settings can be used to generate misleading benchmark results. But it's not actually certain that this is what's happening; the Intel-recommended default behavior for this chip can plausibly produce the reported results—just not in any way that could be reasonably described as "35W".
Even if the configuration may be different from motherboard to motherboard and from laptop to laptop, exactly as wtallis said, most Intel CPUs are configured by default to consume during the first 28 seconds a power 2 to 3 times greater than the nominal TDP, e.g. 105 W for a 35 W CPU.
Most, if not all, subtests of GeekBench need less than 28 seconds, so it is quite possible for the entire benchmark to be run at an 105 W power consumption. Whenever a subtest finishes, the power consumption momentarily drops, which resets the 28 second timer.
If the computer has poor cooling, it may happen that when the CPU spends too much time and too frequently at an 105 W power consumption the junction temperature limit is reached, which triggers thermal throttling and the power consumption is reduced. This is a different mechanism, independent of the one that reduces the power consumption down to the nominal TDP after 28 seconds, or after another configured time.
Thermal throttling reduces the power consumption only enough to keep the temperature under the limit, so the power consumption may remain greater than the TDP until the 28 seconds pass.
Based on the reported benchmark performance, it seems very unlikely that temperature-based throttling kicked in, and it's clear that the chip was operating well above 35W for at least a large portion of the benchmark run. So the PL1 and PL2 turbo power limits are the relevant controls at play here.