Amazon Simple Notification Service (Amazon SNS) First-In-First-Out (FIFO) topics now support 3,000 messages per second, per topic. All existing and future FIFO topics now have this new quota by default, with no configuration change required. To benefit from maximum throughput in FIFO topics where message order is strictly maintained within each message group, distribute your messages evenly over a large number of message group IDs, as messages from different message groups are delivered in parallel.
Source:: Amazon AWS