At that point, the performance of his benchmark depends of DRAM access. In modern system, DRAM is very parallel -- a single access is glacially slow but you can

At that point, the performance of his benchmark depends of DRAM access. In modern system, DRAM is very parallel -- a single access is glacially slow but you can have a lot of accesses in flight. It would appear that a single thread of his benchmark cannot provide enough access parallelism to saturate his DRAM interfaces.