A fire suppression system configured to provide fire suppression to multiple different compartments (14, 16, 18, 20, 22), comprising: at least one first gas source containing an inert gas, the inert gas being nitrogen, helium, argon, carbon dioxide or mixtures thereof; at least one second gas source containing an organic halide gas; a distribution network connected with the at least one first gas source and the at least one second gas source to distribute the inert gas and the organic halide gas, the distribution network including: a common manifold; input lines respectively connecting the at least one first gas source with the common manifold and the at least one second gas source with the common manifold; output lines respectively leading from the common manifold and configured to be connected with different fire suppression compartments (14...22); and flow control devices configured to control flow of the inert gas and the organic halide gas; a detection system for each of the multiple different fire suppression compartments (14...22) that is capable of detecting whether there is a fire threat in the given compartment (14...22); and a controller in communication with the distribution network, the controller configured to distribute the inert gas responsive to a fire threat signal and configured to select which of the multiple different fire suppression compartments (14...22) to initially distribute the inert gas to based upon the location of the fire threat; characterised in that: the controller is configured to determine whether to additionally distribute the organic halide gas based upon a compartment volumetric size and fire suppression need of the type of compartment in which the fire threat is located; and the controller is configured to adjust a flow rate of the inert gas and adjust a flow rate of the organic halide gas based upon the compartment volumetric size at the location of the fire threat. at least one first gas source containing an inert gas, the inert gas being nitrogen, helium, argon, carbon dioxide or mixtures thereof; at least one second gas source containing an organic halide gas; a distribution network connected with the at least one first gas source and the at least one second gas source to distribute the inert gas and the organic halide gas, the distribution network including: a common manifold; input lines respectively connecting the at least one first gas source with the common manifold and the at least one second gas source with the common manifold; output lines respectively leading from the common manifold and configured to be connected with different fire suppression compartments (14...22); and flow control devices configured to control flow of the inert gas and the organic halide gas; a common manifold; input lines respectively connecting the at least one first gas source with the common manifold and the at least one second gas source with the common manifold; output lines respectively leading from the common manifold and configured to be connected with different fire suppression compartments (14...22); and flow control devices configured to control flow of the inert gas and the organic halide gas; a detection system for each of the multiple different fire suppression compartments (14...22) that is capable of detecting whether there is a fire threat in the given compartment (14...22); and a controller in communication with the distribution network, the controller configured to distribute the inert gas responsive to a fire threat signal and configured to select which of the multiple different fire suppression compartments (14...22) to initially distribute the inert gas to based upon the location of the fire threat; characterised in that: the controller is configured to determine whether to additionally distribute the organic halide gas based upon a compartment volumetric size and fire suppression need of the type of compartment in which the fire threat is located; and the controller is configured to adjust a flow rate of the inert gas and adjust a flow rate of the organic halide gas based upon the compartment volumetric size at the location of the fire threat. the controller is configured to determine whether to additionally distribute the organic halide gas based upon a compartment volumetric size and fire suppression need of the type of compartment in which the fire threat is located; and the controller is configured to adjust a flow rate of the inert gas and adjust a flow rate of the organic halide gas based upon the compartment volumetric size at the location of the fire threat.