SFP module in a SFP+ card

Greetings, I was hoping to get some help on a issue I just ran into with a SFP+ card. I recently acquired some Chelsio S310E-CR NIC cards. I read on some forums that they should be compatible with SFP modules even though they are SFP+. For the SFP modules, I went with Ubiquity UF-MM-1G. I have used these in the past and plus they are cheap. When I plug everything in, (drivers included) I get a green link light on the SFP+ PCI card but no link on the SFP switch. I am just wondering if anyone has run into this problem before or something similar.

System Specs are below:
Windows 10 Pro-All the recent updates
32 GB Corsair Vengeance ddr3
Chelsio S310E-CR-Latest Driver
4790K-Stock/No OC
Asrock Extreme 6 z97-Most recent Bios version
Samsung 850 Evo
5 Hard drives of diffrent sizes above 1tb

Switch Specs:
Tested with Cisco SGE2010 and Ubiquity EdgeSwitch 12 (ES-12F)

Fiber cable is known good,
multiple SFP modules were tested to verify it was not the SFP module. I am using this system to edit videos and have upgraded my Freenas Box so I was hoping to up the speed a little bit more before buying a sfp+ switch.

It really depends on how flexible the Chelsio gbics’s and the switches are, if you can force 1Gbs negotiation and use only SFP modules on both ends there is a slight chance that they will work.
However down rating is vendor specific black magic, as many gbics dont support lower speeds unlike ethernet which can auto negotiate a wide range of standards.
Also if you try down rating, you have to manually set both the switch and the card to run at the 1Gbs negotiation. Probably also have better luck with the Ubiquity switch as Cisco switches are picky as all hell. Hope that helps.

First of all, let’s check on your devices one by one.

Chelsio S310E-CR NIC

Chelsio S310E-CR NIC cards is an open vendor who can use third party’s module. So using Ubiquiti module is not a problem.

Ubiquity UF-MM-1G and Fiber Cable

The modules you have are only supporting multimode fiber, so you should check on if your fiber cable is multimode or not. If you use single-mode fiber, it is not strange that your connection is not linked up.

Cisco SGE2010 and Ubiquity EdgeSwitch 12 (ES-12F)

It’s no problem that Ubiquiti modules are used in Ubiquiti switch, but using in Cisco switch may cause some problems. Because Cisco switch would not accept the Ubiquiti modules.


As for the NIC, I suggest that you use 1G NIC card.

To make the link between NIC and Ubiquiti switch, Ubiquiti modules should be fine, which you need to test again.

For the link between NIC and Cisco switch, I recommend you employ third party modules.

10Gtek 1000Base-SX SFP 850nm, 550-Meter, with DDM | SFP-GE-S

This is a professional transceiver vendor, who manufactures transceiver compatible with Cisco and Ubiquiti.

Don’t do it, you shouldn’t do it… going to do it anyway… internal screaming


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