1. A method for execution by a processing module of storage unit of a dispersed storage network, the method comprises: receiving an encoded data slice to store; determining a slice length of the encoded data slice; comparing the slice length of the encoded data slices to a plurality of fixed storage widths, wherein physical memory of the storage unit is divided into a plurality of memory containers, wherein each of the plurality of memory containers includes a plurality of memory bins, and wherein each of the plurality of memory bins of one of the plurality of memory containers has one of the plurality of fixed storage widths such that, from memory container to memory container, the storage widths of the plurality of memory bins have differing ones of the plurality of fixed storage widths; selecting one of the plurality of memory containers based on the comparing to produce a selected memory container; identifying an available bin of the plurality of bins of the selected memory container; and storing the encoded data slice in the available bin.