Constant MIN_WORKING_SET 

pub const MIN_WORKING_SET: u64 = _; // 8_192u64

The smallest working set a curve is measured at, in bytes moved per pass.

Low enough to catch the bottom of the ramp, which is further down than it looks: on an M2 Pro the curve is already within 12% of the bus figure at 256 KiB and only falls away below that — 146 GB/s at 128 KiB, 94 at 64 KiB, 11 at 8 KiB. A sweep starting a few hundred kilobytes up would report an almost flat curve and miss the effect it exists to measure.