MikroTik CSS318-16G-S+IN Management
As the “CSS” name suggests, this is a MikroTik SwOS switch. Many STH readers are familiar with MikroTik RouterOS. SwOS is the simplified OS for switches.

We get some nice-to-have features like SFP information in the UI. We are just going to show the screens here since they are fairly self-evident and we want to give folks a flavor of SwOS.

Here is a shot at the Port Isolation.

Here is link aggregation.

This is the forwarding screen.

This is RSTP.

Here is the VLAN setup screen:

This is the ACL screen:

This is the System tab.

Something small, but also nice that MikroTik has that many other switches in this price range do not is the ability to update either via file repository. That may seem like a small feature, but it makes things very easy to update.

Next, let us discuss performance.
MikroTik CSS318-16G-S+IN Performance
Here is a quick look at MikroTik’s numbers for the switch:

Our numbers largely mirrored what we would expect.

Overall, 1GbE and 10GbE switch silicon is mature at this point, so this is what we would expect.
MikroTik CSS318-16G-S+IN Power Consumption
In terms of power consumption, we saw 3.3W at idle.

Adding a 1GbE port linked up made power consumption jump to 3.6W.

Adding a SFP+ to 10Gbase-T adapter saw power hit 5W.

MikroTik says that the switch uses 10W maximum without attachments and 13W at most, making this a relatively low-power switch. Also, since it is fanless, it is quiet.
MikroTik CSS318-16G-S+IN 10″ Rack Install
Installing this into racks, MikroTik supplies both full-width and half-width rack ears.

Here is a quick look at the switch in a DeskPi 10″ rack switch:

Something small that we noticed is that we could only install it on one side. One side of the rack allowed the switch to fit easily. The other side left this switch a few mm too wide.

At first, we thought that was a fluke, but it happened on other 10″ racks as well. For example, in the video, we showed how we had to untighten the posts on another rack to fit the switch.

This led to a strange observation. Unlike the 19″ rack sector where rack widths are very consistent, we ran into challenges with four of the six 10″ racks we tried, mostly due to the quality control of screwing in posts in adjustable racks.

This is the type of thing that can be very frustrating for folks. In the future, it would be nice if MikroTik made its chassis slightly narrower and its rack ears slightly longer to account for this 10″ rack variance (this had no problems in 19″ racks.) It feels like MikroTik built the CSS318-16G-4S+IN to a 222.25mm or 8.75″ spec, but in the 10″ rack world, things can often be slightly out of spec. Given its width, even putting it on a 10″ shelf instead of rack ears is challening because most 10″ rack shelves assume a bigger variance of rack widths, so they do not have enough room to accomodate the switch. MikroTik needs to shave a few mm from the width of this to make it fit better. It is really strange they did not do so.
Final Words
At a $139 list price, we are already seeing street pricing in the $107-115 range. While this is a far cry from some of the cheapest switches in the segment, if you just need this port configuration from a switch designed in Latvia and built in Malaysia, then this is a good option. Still, the talk around STH was more about how much more useful this would be if it was a 2.5GbE switch, and/or had PoE+ capabilities. 1GbE is quickly becoming the domain of management interfaces, small developer boards like Raspberry Pi’s or the NVIDIA Jetson Orin, and older Project TinyMiniMicro nodes. It would certainly cost more, but we wish MikroTik made this. MikroTik has the CRS318-16P-2S+OUT aka the netPower 16P, but that is meant for outdoor PoE+ installation, not 10″ rack installation.

The fact that we want more does not make this bad. Indeed, if you just need 1GbE and the narrower form factor, then the MikroTik CSS318-16G-2S+IN is a neat little form factor switch.
Needs 2.5Gb
If they release this with 4 SFP+ and 2.5GbE it’s going to be a best seller I think. Should easily be possible with the new Marvell Prestera chips that Mikrotik uses.
Why do companies keep releasing new products with 1GbE ports? Very frustrating when I see something that checks all but one box. Feels like I’m back in 2003 when looking for gigabit devices and running into 100Mbit products everywhere.
I agree with David – if they were to release this with 4x SFP+ ports AND 2.5GbE on the rest of the switch, it would hands-down be one of if not THE most flexible and desirable home/small-business switches on the market. 10 inch rack compatibility or not.
A bunch of gigabit jacks and just two SFP+ ports though? Meh, pass.