UK The short answer
SFP+ is a modular cage that accepts fibre or direct-attach copper and is the more practical choice for industrial deployments. RJ45 (10GBASE-T) runs over standard twisted-pair copper and suits shorter indoor runs where cabling is already in place.
The two options solve the same problem but trade off differently on distance, electromagnetic tolerance, and deployment flexibility. Each has its place.
Where SFP+ wins
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Longer transmission distances Fibre links run hundreds of metres or more; direct-attach copper (DAC) cables work well for short rack-to-rack runs without transceivers.
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Better electromagnetic tolerance Fibre is immune to EMI, which matters in industrial environments with motors, drives, and high-current equipment near the cable run.
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Mixed-media flexibility The same SFP+ port accepts fibre or copper by swapping the transceiver, which simplifies sites running both within one cabinet.
Where RJ45 (10GBASE-T) wins
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Reuses existing copper cabling Cat 6a or Cat 7 installations often already support 10GbE without re-cabling, useful for retrofit projects.
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Simpler termination Standard RJ45 connectors are familiar to most installation teams and don't require fibre-handling training.
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Lower per-port cost No separate transceiver module required at each end, which adds up across larger port counts.
Which to specify
In practical terms, SFP+ tends to be the right choice for industrial and edge AI deployments where EMI, distance, or mixed fibre/copper topologies are in play. RJ45 10GbE remains a reasonable option for shorter indoor runs in cleaner electrical environments where Cat 6a/7 is already deployed.
For a fuller view, see our pillar article: Why edge AI is outgrowing 2.5GbE.