A data center cooling system, comprising: a server rack sub-assembly that comprises at least one motherboard mounted on a support member and a plurality of heat generating electronic devices mounted on the at least one motherboard; at least one cold plate positioned in thermal communication with at least a portion of the plurality of heat generating electronic devices, the cold plate configured to receive a flow of a cooling liquid circulated through a supply conduit fluidly coupled to a liquid inlet of the at least one cold plate, through the at least one cold plate, and through a return conduit fluidly coupled to a liquid outlet of the at least one cold plate; and a modulating control valve mounted on either of the motherboard or the support member and positioned in either of the supply conduit or the return conduit, the modulating control valve configured to adjust a rate of the flow of the cooling liquid in response to receiving a command from a controller, the command configured to adjust the valve based at least in part on an operating condition of at least one of the plurality of heat generating electronic devices; the controller communicably coupled to the modulating control valve, and configured to: determine an operating temperature for each of the plurality of heat generating electronic devices; determine a maximum operating temperature corresponding to a hottest electronic device from the determined operating temperatures; and calculate a thermal margin between the maximum operating temperature and a minimum or average of the determined operating temperatures; and adjust the modulating control valve to open or close based on the determined thermal margin to a new valve position between a predetermined minimum open percentage higher than 0% and a predetermined maximum open percentage lower than 100%. a server rack sub-assembly that comprises at least one motherboard mounted on a support member and a plurality of heat generating electronic devices mounted on the at least one motherboard; at least one cold plate positioned in thermal communication with at least a portion of the plurality of heat generating electronic devices, the cold plate configured to receive a flow of a cooling liquid circulated through a supply conduit fluidly coupled to a liquid inlet of the at least one cold plate, through the at least one cold plate, and through a return conduit fluidly coupled to a liquid outlet of the at least one cold plate; and a modulating control valve mounted on either of the motherboard or the support member and positioned in either of the supply conduit or the return conduit, the modulating control valve configured to adjust a rate of the flow of the cooling liquid in response to receiving a command from a controller, the command configured to adjust the valve based at least in part on an operating condition of at least one of the plurality of heat generating electronic devices; the controller communicably coupled to the modulating control valve, and configured to: determine an operating temperature for each of the plurality of heat generating electronic devices; determine a maximum operating temperature corresponding to a hottest electronic device from the determined operating temperatures; and calculate a thermal margin between the maximum operating temperature and a minimum or average of the determined operating temperatures; and adjust the modulating control valve to open or close based on the determined thermal margin to a new valve position between a predetermined minimum open percentage higher than 0% and a predetermined maximum open percentage lower than 100%. determine an operating temperature for each of the plurality of heat generating electronic devices; determine a maximum operating temperature corresponding to a hottest electronic device from the determined operating temperatures; and calculate a thermal margin between the maximum operating temperature and a minimum or average of the determined operating temperatures; and adjust the modulating control valve to open or close based on the determined thermal margin to a new valve position between a predetermined minimum open percentage higher than 0% and a predetermined maximum open percentage lower than 100%.