10Gtek 25G SFP28 SFP+ SR Transceiver, 25GBase-SR Duplex LC MMF Optical Module for Cisco SFP-25G-SR-S, 850nm, DDM, up to 100m

Works great on my ConnectX 4 LX

I'm using this w/ an optical breakout box and it worked just fine! I'm got just 3 of 4 25Gb links on this transceiver to other switches/devices.... Two are at 25Gbps, the other is 10Gbps. One goes to an Intel, one to a Mellanox card & to another Mikrotik switch. The only problems I had were Mikrotik-related quirks that prevent auto-negotiation of speed. But setting speed manually + FEC91 mode and it's been solid.

It works

I purchased these 7 months ago and they were connected with about 75 meters of single mode fiber, and they have degraded to the point of only passing about 200 megabits. I believe they would be ok if I had used attenuators.

I was really hoping that this would be the part I needed but unfortunately it was not. I am sure there is a nuanced communication issue here but for the life of me I can't find what is the sticking point. My use case was to create a link between my router (mikrotik ccr2204) and the rest of my switch stack. I was not able to get any communication over this line even with other 10gtek receivers (40g and 100g) and all my attempts to get support from 10gtek were met with radio silence. This is a shame as I have had great luck with other parts (dac's, 40g, etc) but this one needs something but I just could not figure it out.

Very affordable, worked with Solarflare on-load NIC, and is stable for months of runtime now.

They just works!

Works without any fuss with my QNAP 25Gb switches / NICs (I believe these are rebranded Mellanox units, or at least using Mellanox chips). I have been purchasing 10Gtek optics and DACS for some time, in 1G/10G and 25G variants and they have always been excellent. I would recommend them to anyone.

Beware before purchase! Initially I ordered 2 and they seem to work fine until I start to notice performance issues. It took me some time to trace the issue down to an incompatibility between these transceivers and Ubiquiti switches. I ordered 4 more which all show the same major performance issues (down to ~ 30 Mbps under some circumstances. I have tried several other brands including Ubiquiti transceivers and they all work fine. None of these 10GTek work without a problem. I mailed support via their website, They boast good technical support but I never got a reply. I can return 4, but the first order I can no longer return and there is no support. Think twice! Pay a little more.

Fait tres bien le boulot, faut juste faire attention, il n'est pas multi vitesse: certains modules sont compatibles 10Gb et 25Gb, celui la est uniquement compatible 25Gb.

Got one of these in a Mellanox ConnectX-4-Lx card and it won't negotiate down to 10Gb talking to a 10gb 10Gtek module in my TP-Link 3008 - don't know why as it's supposed to be able to. Updated the card with the latest firmware (in case that was the issue) and still no joy. Gave it 3 stars as I will keep the module and when I upgrade the switch to 25Gbe I will try again then and my other 10Gtek modules have worked flawlessly so maybe it's user error?