Development and evaluation of file-system software Spectral, using DAOS file-system backend. Spectral is a portable intercept library for redirecting HPC file output (write-only) to fast pools (nvme/tmpfs) of storage using weak consistency or pram consistency. Spectral leverages the distributed non-overlapping nature common in large scale HPC I/O to eliminate metadata and locking overhead to reduce the overhead of I/O on scientific simulation progress. Spectral is portable in that applications that can suitably use Spectral do not need to make source code modifications to use Spectral.