The present disclosure relates to a processing resource for a graphics processing system for performing graphics processing for an application executing on a host processor of the graphics processing system according to a command stream, the command stream being generated by the host processor in response to an API call from the application, the processing resource comprising: a control circuit configured to execute commands from the command stream, wherein the command stream comprises one or more commands relating to a processing task and one or more commands relating to at least one state group associated with the processing task; at least one processing circuit configured to perform processing tasks; a shadow state storage module configured for use by the control circuit to store state information; and a processing state storage module configured for use by the processing circuit to store state information, wherein the control circuit is configured to determine one or more changed states within the at least one state group with respect to a preceding API call, to write state information comprising the one or more changed states to the shadow state storage module, and to assign the processing task to the at least one processing circuit and execute an instruction to transmit the state information from the shadow state storage module to the processing state storage module.