10G MGBE poor performance under high load

Is it normal that MGBE can only reach 7Gbps when the system is busy? We use stress-ng to stress CPU and iperf3 to test MGBE. BSP is R38.4.0, MTU is configured to 9000, and power mode is 120W. Whether threaded mode is enabled, the performance is poor.

Please try with JetPack 7.2. Thanks