Comment by diamondlovesyou

AMD's string store is not like Intel's. Generally, you don't want to use it until you are past the CPU's L2 size (L3 is a victim cache), making ~2k WAY too small. Once past that point, it's profitable to use string store, and should run at "DRAM speed". But it has a high startup cost, hence 256bit vector loads/stores should be used until that threshold is met.