StarTech.com Dell EMC QSFP-40G-ESR4 Compatible QSFP+ Module - 40GBASE-SR4 - 40GbE Multimode Fiber MMF Optic Transceiver - 40GE Gigabit Ethernet QSFP+ - MPO 400m - 850nm - DDM

Product Overview

AI-generated summary

At ~£38 ex-VAT, this StarTech QSFP+ module is one of those “sensible if you’ve checked compatibility” buys. The big catch with SFP/QSFP optics isn’t performance on paper—it’s whether your switch/router will actually accept it and whether you’re comfortable with third‑party behavior (DDM support helps, but that’s not the same thing as perfect DOM compatibility in every vendor setup). If you’re running Dell EMC gear and you’ve already found these work in your exact model/firmware combination, this is a cost-effective way to light up 40GbE on multimode without paying Dell-brand pricing.

I’d recommend it for budget-conscious teams maintaining existing data centre/server networking where they just need more ports to work reliably (and they can validate optics before committing). It’s not the right choice if you need “plug in and forget it” on day one across a mixed fleet, or if you can’t easily test in your specific environment—optics are one of the few network components where small incompatibilities can turn into annoying downtime. Bottom line: good value **if** you can confirm it’s supported in your exact Dell EMC QSFP+ slot/module compatibility scenario; otherwise, I’d spend a bit more on optics you know your switch will accept first time.