[kllrnohj]

How would SIMD do anything to address the problem's fundamental anti-cache-friendly access patterns? You'd need to restructure the problem to be cache-friendly, but SIMD won't really be relevant to that.

[robko]

You can use both at once. Usually, you'd have something like 64x64 tiles in cache and use 4x4 or 8x8 tiles for SIMD.