  We derive a simple algebraic criterion to select the optimal detector network
for a coherent wide parameter-space (all-sky) search for continuous
gravitational waves. Optimality in this context is defined as providing the
highest (average) sensitivity per computing cost. This criterion is a direct
consequence of the properties of the multi-detector F-statistic metric, which
has been derived recently. Interestingly, the choice of the optimal network
only depends on the noise-levels and duty-cycles of the respective detectors,
and not on the available computing power.
