Why 4 SQS FIFO with not batch to reach 1000 msg/sec during a peak demmand and not 2 SQS FIFO each with a btach of 2 msgs?

Hi guys I would like to take out a doubt. The solution to this question is a little bit controversial.

Ok, You can use 4 SQS FIFO in batch mode and reach the rate of 1200 msg/sec.

But I could use 2 SQS FIFO in batch mode each with a batch of 2 messages reaching the same 1200 msg/sec. I just follow the solution reason, If each with a batch of 10 has a batch of 3000 msg/sec, then with a batch of 2 messages then 600msg/sec.
Why not? Did not I get something?

According to High throughput for FIFO queues - Amazon Simple Queue Service and Quotas related to messages the limit of FIFO is 300 (ReceiveMessage) operations / second.

If you have 1000 messages / s:

• 1000 / 300 = 3.33, round it up => 4 messages per batch required to process 1000 messages / s.
• Your 2 messages per batch would only result in 600 messages / s being read.

These limits are per queue, not per consumer of a queue and not across all queues.