> which is essentially what "Unified Memory" is.

Unified memory is when CPU and GPU can reference the same memory address without things being copied (CUDA allows you to write code as if it was unified even if it's not, so that doesn't count, but HMM does count[1])

That is all. What technology is underneath is hardware detail. Unified memory on macs lets you put something into a memory, then do some computation on it with CPU, ANE, ANA, Metal Shaders. All without copying anything.

DGX Spark also has unified memory.

[1]: https://docs.nvidia.com/cuda/cuda-programming-guide/02-basic...