We should not use any AUTOMOTIVE SoCs, as they will eat your battery and heat your home.
We need the MOBILE versions of the SoCs.
Shouldn't this be more a question of efficiency?
I.e. if the automotive SoC is designed to run flat out 100% on 10 cores continuously with a giant heat sink & fan in an automotive application, it could still hypothetically be more thermally efficient with only 2 cores running and underclocked to fit the Pyra thermal envelope than option B if option B is made on a larger process and requires more external components.
It isn't just a matter of what a chip has as a rated maximum power draw, but what chip is most efficient when restricted to the device's maximum power draw. Efficiency is more complex than the raw ratings.
That said, I have no idea what would be able to be enabled/not and how far it would have to clock down to get the power draw/dissipation within the Pyra's envelope. BUT - this automotive SoC will likely have long availability and has a readily available dev kit.
Any dev kit should/could be able to be 'tuned' via core count & underclocking to match the Pyra's thermals (to be determined) so that the package thermals fit inside the envelope - then benchmarked to see if that SoC performs better/worse than other options when limited to the device constraints.
The above argument is not specific to any one SoC, but a concept proposal for SoC selection where we don't simply look at raw 'flat out 100%' numbers for heat OR performance. Rather, what performance can be wrung from any given SoC at the power levels allowed by the rest of the package (Pyra)?
Yes - race to 0 and all of that too. It's complicated. As a general rule though, maybe define the needed capabilities (peripherals, # of cores) then find the SoC meeting those capabilities while running on the smallest lithography process (28nm, 14nm, 10nm, etc.) then underclock to fit the thermal envelope.
OMAP 5432 is 28nm
RCAR H3 is 16nm
Of particular interest to this crowd is graphics.
OMAP 5432 uses SGX544 MP2 rated at 6.2 Gflops
https://en.wikipedia.org/wiki/PowerVR
RCAR H3 uses GX6650 rated at 230.4 Gflops
https://en.wikipedia.org/wiki/PowerVR
I have no idea how much of that graphics processing horsepower would be available with the main CPU throttled way back to maximize the GPU's proportion of the thermal envelope. I'm using this SoC as an example. There are likely better ones out there. Mostly phrasing the questions to find answers to in the selection process.
Efficiency is tied more or less directly to the proportion of directly on-chip supported peripherals, unit price, and the lithography used in the die. Beyond that, isn't just a matter of underclocking to fit the thermals?
