i2800's L4 HTTP requests per second is lower than the 4000s

I would like to know why the L4 HTTP requests per second on the i2800 is lower than the 4000s? The rest of the specs on the iSeries is higher except for that item. Below are the specs from the hardware datasheet:

 

BIG-IP i2800:

 

• L7 requests per second: 650K
• L4 connections per second: 250K
• L4 HTTP requests per second: 1M
• Maximum L4 concurrent connections: 14M
• Throughput: 10 Gbps L4/L7

BIG-IP 4000s:

 

• L7 requests per second: 425K
• L4 connections per second: 150K
• L4 HTTP requests per second: 1.25M
• Maximum L4 concurrent connections: 10M
• Throughput: 10 Gbps L4/L7