[trifurcate]

Because you don't want any AVX512 binary to get stuck on a P-core forever.

[codetrotter]

Also, if application developers got to choose all of them would build their apps to request the most performance. And then how do we put anything on an efficiency core if every application claims to need to run on a P core. Back to square one it is.

[picture]

Why not use a prominent OS display "power efficiency" so the user can harass devs about a calendar app running on P core

[tedunangst]

Because your calendar app happens to use a jpeg decoding library that uses "high power" instructions.