I am using the 5009 as a gateway for my office. I have bought a Mikrotik 10GbaseT SFP module I use with upstream link, the rest is local stuff. The SFP becomes very hot at the point that it either gets shut down or gets downgraded to 1GBaseT. ATM I have a small USB-powered fan attached to the RB50…

Hi Search the Forum for "hot SFP" or other similar keywords. One of the first answers point to SFP module is extremely hot Another [image] HOT S-RJ10 MikroTik hardware general Hi, I have a 5009 with eth1 used at 2,5Gbps as WAN (FO) and I bought some S-RJ10 …

Depending on what kind of device you have attached to RB5009, you can use DAC cable, which runs on lower temperature.

Cool! (Pun is intentional) When typing I was not suggested that specific thread, only the “hot plug one” which is hot, but doesn’t plug into my issue. Thanks anyway.

The 10GbaseT SFP module is attached to upstream CAT6 cable, which is about 20m long. So no DAC possible there. Thanks anyway.

[image] Uqbar: Cool! (Pun is intentional) Cool down man :slight_smile: :slight_smile:, the trail is already blazed :slight_smile: P.S. It was also intentional

SFP+ RJ45 modules tend to work Hot, and that is clearly writen on Mikrotik docu i think. I personally use 10gTek Sfp+ rj45 module that works a lot cooler then mikrotik branded one. But plan to change to fiber optic asap to get cooler temperatures on my rb5009. Highly recommended this one https://a…

[image] Uqbar: I have bought a Mikrotik 10GbaseT SFP module I use with upstream link, the rest is local stuff. The SFP becomes very hot This module is only supported in actively cooled devices (i.e. with a fan). It says so on the product page: “Any MikroTik device with active cooling that …

Those statements are there since quite some time, and this is why I decided to buy one. Unfortunately “extra cooling” is rather vague. I am not asking you to advertise for those SFPs. But knowing which ones get less hot would be nice.

Then I read several rumours that the newer version modules are working on lower temperature. If you bought your devices long time ago, you can consider buying a newer model. Or in alternative case, you can change to optical transmission, if it is suitable for you.

[image] magicc12: alternative case, you can change to optical transmissio ATM F.O. is not an option for me as pulling new cables is not possible. I will wait for some feedbacks on 10GbaseT modules to make a choice.

RB5009: how to cool it?

Hardware

BartoszP March 18, 2026, 6:58am 2

Search the Forum for "hot SFP" or other similar keywords.
One of the first answers point to SFP module is extremely hot

Another