<example of dramatically underclocked mobile GPU>
<examples of barely underclocked mobile GPU>
You're both right. The issue is that Nvidia don't
need to downclock their mobile GPUs because they've always been pretty good at choosing the sweet spot on the performance/voltage curves of their silicon.
AMD, on the other hand, typically push their silicon to the limits of their voltage and clockspeeds. If you bolt a fat cooler onto it, that works great for desktops, but not for mobile.
We'll have to see what AMD do with their mobile parts, but if they want to compete with Nvidia
right now, they can't be too aggressive with clocks and voltages. The 1181MHz indicates that they're aiming for a low TDP, and at a guess from Navi drivers, that is the highest speed the 7nm silicon will go whilst operating at its
minimum voltage*. Beyond that, more voltage is required which exponentially increases power use in order to tap into the performance offered by higher clockspeeds.
More importantly, it's likely that RX 5300M solutions will be in the market when Nvidia makes the transition to 7nm, so (and I'm REALLY guessing now), I'd think Lisa is actually trying to make something that is perhaps not the most profitable thing in the world, but that offers a low-enough TDP to be appealing to OEMs for design wins even once Nvidia's mobile 7nm parts are on the table.
* - (to clarify, the GPU cores can run at lower voltage than the driver-exposed minimum voltage, but I believe power savings beyond the exposed minimum are minimal because the VRAM won't operate at sensible frequencies at all below a certain voltage. On desktop where there are no power concerns at idle states, there is no point even exposing these lower voltages to the user. You get 750mv as the baseline because that's what the GDDR6 needs to operate, and if the GPU draws 7W instead of 6W at idle because of this, nobody is going to care - especially not in a machine with a ~200W GPU and ~125W CPU).
