> If not, is there an easy way to get 90-95% of the way there?

Use `bs=1M`

It'll give you more than 95% optimal performance over more than 85% your devices, from slow USB2/3 flash drives, SD cards and hard-drives to NVMe SSDs and even RAM-only devices such as `/dev/zero`.

Source?

Voices in my head.

And some empirical testing over 10+ years combined with pseudo-scientific benchmarking and biased common sense.

Hey, you asked about the _easy_ way!