[sliken]

How so?

Memory bandwidth (peak, not stream)

  Ryzen 7950x =  84GB/sec #  128 bit wide ddr5-5200
  M1 =           66GB/sec #  128 bit wide ddr5-4800
  M2 =          100GB/sec #  128 bit wide ddr5-6400
  M1/M2 Pro =   200GB/sec #  256 bit wide
  M1/M2 Max =   400GB/sec #  512 bit wide
  M1 Ultra  =   800GB/sec # 1024 bit wide, m2 ultra not out

800GB/sec / 84 = 9.5. Although the ARM64 has a more relaxed memory ordering and generally you see a greater fraction of peak in the real world. Also Mac's default to a 16kb page, which helps the TLB with random workloads. Memory bandwidth is part of why the Apple iGPU does so well when compared to Intel and AMDs best iGPUs. Similarly the improved memory system is why the PS5 and XboxX does so well on games.

Sadly AMD is reserved the improved memory system for the XboxX and PS5. Both AMD and Intel limit laptops and normal desktops (except for the expensive HEDT segment like the Threadripper) to 128 wide memory.