Testing a CRS312-4C+8XG destined for office environment and I have to say the noise level is decent at ~4k rpm (as reported by Winbox with ROS 6.49).
The problem is the fans will stop spinning under a certain temperature (~50 Celsius CPU and ~ 55 Celsius PHY), the temperature will quickly rise above 60 Celsius, fans will start spinning again and the cycle will repeat non-stop (ambient 22 Celsius).
This variation in sound is the annoying part.
At the lowest speed (as far as I can tell) of 3800-4000 rpm, the fans are doing a very good job at keeping both CPU and PHY at around 50 Celsius, while being decently quiet.
If future versions of software would allow the user to disable this zero rpm behaviour would be nice.
As a side note, if future versions of hardware would be fitted with larger heatsinks, would be extra helpful.
A quick 16x speedup video: https://streamable.com/lkjn93
I concure, a bit more control over the FAN’s behaviour would be nice!
I understand, when the switch is mounted in it designed location(aka a Data-Center), the Fan noise doesn’t matter at all!
But sometimes it would be nice to implement the Mikrotik Rackmount-Devices (like the CRS312 or CRS328-24P-4S+RM)
in more noise sensitive enviroments. ( Labs, open-plan offices, Home-Networks or even our Desks for Configuration and Tests)
Usually the fan noise itself isn’t a Problem, but the fan pulsing Intermittently will drive anyone insane =)
Thank you for the report!
We have managed to reproduce the issue locally in our labs and look forward to fixing it on upcoming RouterOS versions, unfortunately, I cannot provide an ETA now.
6.49.1 and it seems something has been changed. Not necessarly for the better.
8 minutes after upgrade and reboot the fans were still spinning at 8k rpm. I thought to myself “I should stop sending requests to support” thinking the fans now will be locked at 8k rpm.
Did not notice this behavior when did the 6.49 upgrade.
After ~8 minutes the CPU and PHY were at ~45 Celsius and fans spun down to 4k rpm. They stayed that way for 1 minute and then bam…zero rpm again.
Temperature rose again to 60 CPU and 65 PHY and fans started spinning at 4k rpm until CPU 50 Celsius and PHY 55 Celsius, then again zero rpm.
So no luck yet.
RouterOS 7.4 and the exact same behavior.
Pretty please with sugar on top allow us to disable zero rpm.
Fans @ ~4k rpm are barely audible and are doing an excellent job in keeping the switch cool.
Gave up on some RouterOS features and switched to SwOS.
Fans now remain on even @ 40 Celsius doing 3800-4000 rpm. Barely audible.
Lost phy-temp and CPU load information via SNMP, as SwOS does not provide those.
Seems the device has the capability to always run the fans, but for some reason, the one man team back at MT can’t be bothered to fix such issues.
Spoke too soon.
In SwOS, it seems the fan curve is totally diferent from RouterOS for the same device.
As soon as the CPU hits 50 Celsius, the fans ramp up to 6.5K rpm, becoming way too loud.
As soon as the temperature gets to around 48 Celsius, the fans will slow down to about 4K rpm.
So switching from RouterOS to SwOS is even worse.
I guess during summer time, the fans will stay at 6.5K rpm or even higher.
