A single parallel application running on a multicore system shows sub-linear speedup because of slow progress of one or more threads known as critical threads. Identifying critical threads and accelerating them can improve system performance. One of the metrics that correlate to thread criticality is the number of cache misses and the penalty associated with it. This paper proposes a throttling mechanism called TCPT which throttles hardware prefetchers by changing the prefetch degree based on the thread criticality. © 2013 IEEE.