StarTech.com MSA Uncoded Compatible 2m 40G QSFP+ to 4x SFP+ Direct Attach Breakout Cable Twinax - 40GbE QSFP+ to 4x SFP+ Copper DAC 40 Gbps Low Power Passive Transceiver Module DAC

Product Overview

AI-generated summary

At £37.33 ex-VAT for a 2m 40G QSFP+ to 4x SFP+ direct-attach breakout DAC, this is the sort of “small spend, big convenience” cable I actually recommend—**if your switch and optics setup is genuinely compatible** with the “uncoded/MSA” idea. The best case is when you’ve got spare QSFP+ ports and you need four SFP+ drops to a server, patch panel, or another piece of gear without paying for active optics. Because it’s passive and twinax, it also tends to behave nicely: low power, low fuss, and typically fewer headaches than active DAC/SFP combinations.

Where I’d be cautious: breakout cables are picky. If the switch firmware doesn’t support that breakout mode cleanly, or if the SFP+ side expects something more specific than “MSA-compatible,” you can end up with link-up issues or weird “half-working” behaviour. Also, DAC cable length matters—2m is a sweet spot, but it won’t suit longer runs. If you need reliability across racks, I’d still validate it with your exact switch model and the link partner before buying in volume. For anyone building a short-reach 40GbE-to-4x10GbE breakout setup and comfortable doing that compatibility check, it’s decent value. If you’re unsure about support on either end, I’d pass and choose a vendor-confirmed option instead.