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.

The ramp bottoms out further down than it looks: an Arc iGPU reads 102 GB/s at 64 KiB, 66 at 32 KiB and 17 at 8 KiB, against 110 sustained.