MikroTik CRS305-1G-4S+IN review

The CRS305-1G-4S+IN has four SFP+ cages and one 10/100/1000 Ethernet port. The SFP+ cages support up to 10 Gbit per port, and 1.25 Gbit SFP modules are also supported. Modules are not included, so you buy those separately. With five ports in total, it suits a small job: linking a few 10G devices together, with the single copper port for a Gigabit connection.

MikroTik lists 82 Gbps switching capacity and 41 Gbps non-blocking throughput. The port mix is Gigabit copper plus 10G SFP+. That makes it a fit for a setup where a server, NAS or workstation connects over a 10G SFP+ link, because those are the ports that carry the speed. The only copper port is Gigabit, so any copper device that needs more than that depends on an SFP+ module. Owners report that copper 10GBASE-T SFP+ modules run hot in the fanless case, so that route needs thought. Fibre or DAC-style links are not discussed, so check module choice before you buy.

The switch dual boots between RouterOS and SwitchOS, and you select which one runs. You configure it through WebFig or WinBox. RouterOS supports Layer 3 features, while SwitchOS is switch-only. That choice suits people who are comfortable with MikroTik's tools. If you want a plain unmanaged switch with no setup, the management layer here is more than you need.

The manufacturer's routing test, using 25 IP filter rules and 512-byte packets, gives about 270 Mbps. Owners also complain about weak routing for gigabit internet. Based on that figure and those reports, the Layer 3 support in RouterOS is better treated as a feature for light use. It is not a basis for routing a full gigabit connection. If you plan to use it as a switch, SwitchOS is the switch-only option.

The case is metal, passive and fanless. Owners praise it as silent and low power. MikroTik lists maximum consumption of 18 W, or 10 W without attachments. The tested ambient range is -40 °C to 70 °C. The heat complaint applies to specific modules: owners say copper 10GBASE-T SFP+ modules run hot in this fanless case. Because the case has no fan, the choice of module matters for temperature.

This is not a PoE-output switch. MikroTik publishes no PoE output budget. It does accept PoE input (802.3af/at) on its Gigabit port, with a 12–57 V input range. That means you can power the switch itself over that port if you have a suitable source. It will not power other devices according to the published specs.

MikroTik offers free software updates for the life of the product or at least five years from purchase. For a device that you configure and then leave running, that gives a clear support position.

It suits a homelab or small office that wants a handful of 10G SFP+ links in a silent, low-power box, and is willing to learn RouterOS or SwitchOS. Owner praise centres on its silence and low power draw. The complaints centre on routing speed and module heat. If you need many ports, PoE output, or a router for a fast internet connection, the specifications and owner reports point elsewhere.