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A Maximum Transmission Unit (MTU) is the largest packet size or frame that can be sent along a link. The MTU is specified in octets and is used by TCP to determine the maximum size of a packet per transmission. A large MTU provides less overhead because packet headers and acknowledgments are not consuming space and bandwidth.
However, this could lead to retransmissions or drops if a hop does not support it. On the contrary, a small MTU is not as efficient as overhead increases with packet headers and acknowledgments.
Jumbo frames are Ethernet frames where the MTU is greater than the standard 1,500 bytes and a maximum of 9,000 bytes. The larger MTU provides greater efficiency because less overhead and fewer acknowledgments are sent across devices, drastically reducing interrupt load on endpoints.
In EDA environments, if you are using 10 GB Ethernet or above from end to end, jumbo frames are recommended for EDA workloads because the amount of data sent per message is far greater, reducing processing times and maximizing efficiency. The high-speed network may allow the larger frame sizes without encountering increased collision rates, particularly if you have set the network to full duplex.
While the general assumption is that jumbo frames provide performance advantages for all workloads, measure results in a lab environment simulating a specific workload to ensure performance enhancements.
For jumbo frames to take advantage of the greater efficiencies, they must be enabled end-to-end on all hops between endpoints. Otherwise, the MTU could be lowered, or packets could be fragmented. The fragmentation and reassembly affect the CPU performance of each hop, which affects the overall latency.