@dan "playing wav files from a ramdisk gave best sound" something similar to this (e.g. playing AIFFs from RAM Disk) may have been true on Commodore Amigas, in the 1980s, back when the CPU was 7MHz and disk i/o could theoretically cause an audio drop out.
Given that, IMHO Windows has always been a downgrade from Amiga Workbench, it wouldn't surprise me if maybe some system set ups are less optimal, but if that alternative memcpy exists, it can be tested, empirically, not just subjectively.