A counters array system comprises a memory device having a plurality of addressable memory locations for storing counter-values; a plurality of delta-counter devices. Each delta-counter device is operable to hold a maximum delta-value corresponding to a maximum number of occurrences of an event during a time duration between two counter scans controlled by a scan control unit. Each delta-counter device has an input connected to receive a signal from an event source corresponding to an occurrence of the event, and an output connected to provide a delta-value representing an accumulated number of occurrences of the event to a delta-count update circuit. The delta-count update circuit is connected to the memory device and the counter scan control unit, and being arranged to receive the delta-value and an address of a corresponding counter-value, read the counter-value from the memory device, and provide an updated counter-value incremented by the delta-value to the memory device.