Home > Storage > PowerScale (Isilon) > Product Documentation > Storage (general) > PowerScale OneFS Best Practices > Small file considerations
In practice, a OneFS powered cluster typically delivers 75 to 90 percent space efficiency for a typical dataset. Given a dataset with a wide range of file sizes, it is the large files that dominate utilization, saving as much as 20 to 30 percent of capacity over traditional storage systems. Even when small files make up more than 90 percent of a dataset by file count, they consume only 10 percent or less of the capacity. As such, the efficiencies in storing large files overshadow any inefficiencies in storing small files. Further, as a dataset increases in size, a cluster moves closer to 80 percent efficiency.