MikroTik CRS520-4XS-16XQ-RM Power Consumption and Noise
The power supplies are redundant 150W MikroTik units.
We saw 46-48W power consumption at idle. Depending on the optics you use, it can go up from there quite a bit. MikroTik says that without attachments the switch can use up to 123W but that the maximum power consumption is 150W. That leaves only 27W of headroom for optics. To us, that feels like not enough as a QSFP28 optic can hit 3.5W, although is often less. We rarely saw power consumption much above 100W, but we could see why some users might want 200W power supplies instead for more safety margin.
On the noise front, it was far from silent. At idle we saw 41-43dba but the switch would ramp from there depending on use. It is much quieter than older 32-port 1U 100GbE switches, but it is also nowhere near being silent. This is the kind of switch that would work well in a data closet.
Final Words
Overall, there are two people who are going to look at this switch. On one hand, some may think this is expensive since there are sub $1000 32-port used enterprise switches. If you do not care about power consumption, noise, and a web management interface, then there are a lot of used options out there. On the other hand, MikroTik now has a bigger 100GbE product that can fill a simple niche: people who want to deploy 100GbE to small groups but do not want to learn networking.
I think a lot of folks who get really into networking are going to be disappointed that MikroTik’s biggest offering is not bigger. They may also be disappointed by resources being “wasted” by GUIs. The counterpoint is Patrick’s example of a video studio owner who just wants a relatively inexpensive box that they can plug 100GbE links into and get decent performance for editing. That is what this switch does extremely well.
For users that do not need 16-ports, then MikroTik has other great and affordable options like the MikroTik CRS504-4XQ-IN. If you just need something bigger, then the MikroTik CRS520-4XS-16XQ-RM is awesome. To us, the bigger question is whether this switch will evolve as MikroTik has a lot more performance in the switch chip and management processor than in previous CRS editions. Time will tell on that one.
If you want to use a full 100gbe you kinda need RDMA for windows. I have a 32 port 100gbe and most windows transfers max out around 40gb. Which is fine, I’m sure this switch works great as a 40g switch as well. I also hacked 120mm noctua high pressure fans into the top lid making it very much a TOR router by necessity. So something like this would be great.
However I didn’t go with iwarp compatible nics so there is a decent bit of switch compatibility required. Will they support PFC on the feature roadmap?
I wonder why so many switches go for the 1U full width form factor. You’d think if you went with 2U half width then you could get the same port density by putting two side by side, but you’d be able to use larger, more efficient fans and heatsinks, and quieter fans as well.
Hi, did you test the switch with high power transceivers?
Does it actually support modules with higher power classes. E.g. 80km 100G ZR4 modules will use 5.5W. Some devices will refuse to operate transceivers with a higher consumption than 3.5W.
Given the low power budget left for transceivers it seems like it’s designed for use with only twin ax DAC cables. Even 16 x low power 2.5 watt SR4 transceivers would be a problem. Is there any official word from mikrotik regarding transceiver power budget?
RouterOS 7.15 seemed to have added some initial support for PFC, and 7.16 seems to be refining a bit more.
Here’s the thread on QoS:
https://forum.mikrotik.com/viewtopic.php?p=1089316#p1089316
You can see I asked about clarification on RoCE towards the bottom but haven’t received an authoritative response – only a community member stating “You don’t need DCB support, just use RoCE v2” which I don’t consider to be a great answer. Maybe if yall want to ask as well and help me bring focus?
I’m sure Patrick / STH is also asking Mikrotik, as it came up in previous videos with the 4 port 100Gb CRS 5xx switch.