Ok, so it’s not as simple as bumping the TLAB pointer by 48. Which was my point. You see how that’s multiple times as expensive as stack allocating that many variables? Even something as simple as assigning the class to each object still costs something per object. The stack doesn’t need self describing values because the compiler knows ahead of time exactly what every chunk means. Then the garbage collector has to scan each object’s self description… which way more expensive than stack deallocation, by definition.

You’re extremely knowledgeable on all this, so I’m sure that nothing I’m saying is surprising to you. I don’t understand why you seem to be arguing that heap allocating everything is a good thing. It is certainly more expensive than stack allocation, even if it is impressively optimized. Heap allocating as little as necessary is still beneficial.