Technical Tip: 4 x 10G links not equal to 1 x 40G links on serialization delay

Serialization delay refers to the time it takes to push all the bits of a packet onto the network link. It depends on the link bandwidth (speed) and the size of the packet being transmitted. It's calculated using the formula:

Serialization Delay = Packet Size/Link Speed:​

• Serialization Delay for one 10G link=1,500×8 / 10,000,000,000 ​=1.2μs 
• Serialization Delay for 40G link=1,500×8 / 40,000,000,000 ​=0.3μs

In terms of serialization delay, a 40G link is faster (lower delay) compared to the 4 x 10G links, because the 40G link can transmit more bits per second, reducing the time it takes to serialize each packet.