StarTech.com MSA Uncoded Compatible 1m 40G QSFP+ to QSFP+ Direct Attach Breakout Cable Twinax - 40 GbE QSFP+ Copper DAC 40 Gbps Low Power Passive Transceiver Module DAC

Product Overview

AI-generated summary

For £21.54 ex-VAT, this is the sort of DAC breakout cable you buy when you already know the port side will behave and you just need a reliable, low-latency copper link without paying optics money. If you’re building short runs in a rack/adjacent cabinets—typically within the kind of distances where DACs actually shine—this kind of direct-attach, passive twinax is usually great value. It’s also “plug it in and forget it” compared to active gear, with less to configure and no optical power budget drama.

That said, the honest catch is compatibility. You’re specifically looking at “MSA uncoded compatible,” so this isn’t the safest choice for environments where vendor firmware, strict module-ID checking, or finicky switches might reject non-standard optics/DAC behaviour. If you’ve had trouble before with grey-market DACs or breakout pinouts, I’d be cautious. Also, this category naming is a bit misleading—DACs aren’t USB anything—so make sure your switch/NIC supports QSFP+ breakout and that you’re not mixing “40G breakout” expectations with “100G” or other modes.

**Who should buy:** UK businesses with rack-mounted infrastructure where you want a cost-effective 40GbE copper link and the switch vendor compatibility is already proven (or you’ve confirmed it in advance). **Who shouldn’t:** teams doing mixed-vendor gear, strict compliance environments, or anyone who can’t validate breakout/MSA behaviour—because at this price, the risk isn’t the cable, it’s the “will your hardware accept it?” part.