A data storage device uses a foil disk platter with significantly reduced inertia and weight as compared to the thick aluminum or glass disk platter in a typical hard disk drive. The reduced rotating inertia of the foil disk enables faster spin-up performance which can be used to reduce decrease the power consumed by the unit. In portable appliances that use disk drive storage devices battery life can be extended significantly and the unit can be made thinner and lighter. Certain parameters of the foil disk substrate may be determined, to provide improved control of disk flutter, from a range parameter defined by RANGE = ρ ⁢ ⁢ R 2 Et 2 where ρ=foil disk substrate mass density, R=foil disk substrate radius, E=Young's modulus of foil disk substrate, and t=foil disk substrate thickness. RANGE has dimensional units of s2/in2, and the magnitude of RANGE may be between 10−6 and 3(10−4).