Yeah, and then somebody took care to actually implement and benchmark those cache-oblivious algorithms against the classic algorithms with hard-coded chunk size

Yeah, and then somebody took care to actually implement and benchmark those cache-oblivious algorithms against the classic algorithms with hard-coded chunk sizes and somehow the cache-oblivious ones decisively lost in every single case [0]. [0] Kamen Yotov, Tom Roeder, Keshav Pingali, John Gunnels, and Fred Gustavson "An experimental comparison of cache-oblivious and cache-conscious programs" (2007). https://doi.org/10.1145/1248377.1248394 https://doi.org/10.1145/1248377.1248394