Using LASNEX, the authors investigate the effect of initial fuel aspect ratio on the hydrodynamic efficiency and implosion stability of 1 mg ICF capsules directly driven with 0.27 μm light. It is concluded that these capsules will be either hydrodynamically inefficient, with less than 8% of the incident laser energy converted into fuel kinetic energy, or hydrodynamically unstable, with an in-flight aspect ratio greater than 80, unless the instability growth rate can be reduced to a small fraction of its classical value.