Analysis of information sources in references of the Wikipedia article "Broadwell (microarchitecture)" in English language version.
If the CPU needs to work hard for an extended period of time and the laptop gets warmer, it will slowly ramp down its speed until it's operating at its stated TDP. [...] There are two OEM-configurable "power level" states that define how quick the CPU can be in these situations: PL2 tells the processor how much power it's allowed to use when it needs a short burst of speed, and PL1 defines how quickly the processor can run under sustained load. [...] This is at the heart of what Intel is doing with the Y-series processors: their maximum TDP has been lowered four watts, from 17 to 13. Intel is also validating them for use at two lower PL1 values: 10 watts and 7 watts. This is where the marketing we discussed earlier comes in—rather than keeping these values under the covers as it has so far been content to do, Intel has taken that lowest value, put it on its product pages, and called it SDP.
Configurable TDP (cTDP) and Low-Power Mode (LPM) form a design vector where the processor behavior and package TDP are dynamically adjusted to a desired system performance and power envelope. [...] With cTDP, the processor is now capable of altering the maximum sustained power with an alternate guaranteed frequency. Configurable TDP allows operation in situations where extra cooling is available or situations where a cooler and quieter mode of operation is desired.
