Throughput extremely decreases when IPFW 7000 mac based rules activated

Hi, I have freebsd 11.2 server with IPFW firewall

870Mbits Fiber Net exist in my data center

There are 7000 defined mac based rules on IPFW and 3000 of them active client . There is no problem before IPFW rules loading but when i load IPFW rules,

throughput extremely decreases up to 80Mbits. There are not any error logs. I could not find what is the problem.

Any help would be appreciated at this point.