Adjust the Message Storage slider so that the channel only retains the message data that you will actually need.

One limitation on message throughput is the amount of disk writes that Mirth® Connect's database must perform while processing each message. Reducing the amount of message data retained can increase throughput and decreases memory usage as well as disk usage. Production level guarantees that if an unexpected server failure occurs, any incomplete (received, but not yet fully processed) messages will be automatically recovered and processed on restart. If increased performance is needed, you can to reduce this to the Raw level, which only retains the original raw message prior to being processed by any transformer steps. Incomplete messages can still be recovered on failure, but must be done so by manually reprocessing them. Keep in mind that using destination queues requires at least Production level.