It's rather that WriteFileGather is the Windows version of writev on Unix. According to https://man7.org/linux/man-pages/man2/writev.2.html#CONFORMING_TO https:

It's rather that WriteFileGather is the Windows version of writev on Unix. According to https://man7.org/linux/man-pages/man2/writev.2.html#CONFORMING_TO https://man7.org/linux/man-pages/man2/writev.2.html#CONFORMI... writev exists since 4.2BSD, which according to Wikipedia is older than even Windows 1.0 (which probably didn't have WriteFileGather yet, I don't think 16-bit Windows had OVERLAPPED). Also, looking at the documentation for WriteFileGather, it seems more limited than writev. WriteFileGather seems to require that all buffers are page-sized and page-aligned, while writev can gather arbitrary-sized and arbitrary-aligned buffers.