Systems and methods for preventing excessive buffering of transactions in a coherence point. The coherence point uses a lookahead mechanism to determine if there are enough credits from the memory controller for forwarding the outstanding transactions stored in the IRQ. If there are not enough credits, then the coherence point prevents the switch fabric from forwarding additional transactions to the coherence point. By preventing excessive buffering in the IRQ, the QoS-based ordering of transactions performed by the switch fabric is preserved.