This suggests that Nvidia's TGPs (tabulated earlier) are not the real points where adding more power provides very little benefit, and certainly not enough to keep performance reduction negligible from a non-Max-Q variant of the card.

So I have some speculations on ways that the 1080 (notebook) Max-Q’s current state could have been achieved without needing to use (and charge for) a 1080. Let’s step back for a moment and take a look at the GTX 1070 (notebook). This card is not the desktop card in notebook form; nay, it is actually a bit better by its specifications: The 1070 (notebook) cards have 2048 cores, as opposed to the 1070 (desktop) cards. At the same time, they have a relatively low power limit (around 115W) and as such, get power-limited very quickly and do not hold high boost clocks when the cards are stressed. As referenced by another excellent video by Digital Foundry, however, the reduced clockspeeds are not of much concern when compared to their desktop brethren because the larger core count renders the effective performance the same, even at low boost speeds. This allows the 1070 (notebook) to generally compete with its desktop counterpart in performance.

If the heat dissipation of 110W of power as a maximum was the aim of Max-Q, then the 115W 1070 (notebook) cards have pretty much already achieved this. In fact, a lot of the more enthusiast users of notebook forums have taken to using MSI Afterburner to reduce the voltage curve of the GPUs (a lot of ASUS forum users in particular), resulting in higher boost clocks and much lower temperatures. Some of the 1070 (notebook) card owners have opted to lock their core clocks to 1750MHz maximum boost and use anywhere between 0.825v and 0.875v for that frequency range. Temperatures are reportedly down and their cards hold the 1750MHz boost frequency almost 24/7 under load — something that did not happen when the card was left stock, due to power, temperature, or voltage regulation throttling. This makes sense since voltage is directly related to both heat and power consumption, and 10-series (notebook) cards generally use up to 1.063v under stock operating conditions (usually sitting around 1.05v on average when stressed). Reducing voltage reduces the power consumption for the same performance as the power limit “stretches” further and the cards can clock higher. The gap in voltage between 0.875v and 1.05v is extremely large and is a testament to the efficiency the existing, non-Max-Q 1000 (notebook) cards are capable of when configured in such a way.

Please do note, however, that there is no way for an end-user to truly set a specific voltage on any Pascal GPUs, and that there is a downside to this method of voltage curve tweaking. Lowering the voltage also reduces stability, and a balance should be found. Not every user can simply run 1800MHz at 0.8v and call it a day as each card is different, but from all the information I have been able to find, a smarter voltage curve can provide a HUGE benefit to efficiency, reducing temperatures while improving performance. In fact, one particular user has been able to ballpark the 1080 (notebook) Max-Q’s 3DMark Firestrike graphics card score while only using 100W on purpose from his regular, non-Max-Q 1070 (notebook) card, simply by using the same voltage reduction method. Another enthusiast was able to get his clockspeeds all the way up to 1974MHz without even crossing 1v used, owing testament once again to the efficiency that the existing non-Max-Q cards are capable of.

To further prove this possibility, a fellow enthusiast ran some tests by locking the clockspeed of his 1070 (notebook), limiting the power draw limits in stepped segments. The table below proves that the efficiency breakpoint of 110-115W is for the 1070 (notebook) with an upper limit of 150W for the stock boost frequency (note that it does NOT indicate power drawn per test, just the limit set via software). Therefore, a 1080 (notebook) almost certainly has a higher actual breakpoint than the 110W the Max-Q is capped at, but the 110W breakpoint is actually a perfectly good fit for the 1070 (notebook) with a proper voltage frequency curve.

This suggests that Nvidia's TGPs (tabulated earlier) are not the real points where adding more power provides very little benefit (and certainly not enough to keep performance reduction negligible from a non-Max-Q variant of the card).