How quiet can a Mellanox SX6036 be made?

[naptastic]

I have two SX6005 switches, and learned the hard way that opening the chassis to replace the fans triggers chassis intrusion detection, and now I can't manage the switches at all. At least they still pass traffic.

Replacing the four Delta fans with Noctuas, and leaving the PWM pin floating so they're always at 100%, I find them tolerable. But a completely unmanaged switch with no Ethernet capability is really holding me back so I'm considering buying an SX6036.

Can the fans be replaced with Noctuas? If anyone has done so, how configurable are fan speeds on the SX6036? Lower speeds are a "nice to have" as long as temperatures stay okay, but if they have to run at 100% that's okay too.

Thanks everyone on this forum who has figured out how to get the most out of this generation of hardware. It really is transformative to have a homelab where the network is never the bottleneck.

 

[Freebsd1976]

there shoud no "chassis intrusion detection" things , but need the fan rpm than 4096 or 4500, otherwise fan led show red .
sx6036 is the same

 

[sko]

Can the fans be replaced with Noctuas?

No. Because they have EXTREMELY low throughput and won't have any airflow with the tiniest amount of static pressure. Noctua fans are for applications where you have almost no heat dissipation and hence the very lowest airflow requirements, not for anything demanding decent amounts of air being moved.

Just look up the datasheet for those fans and try to find something that provides at least ~60-70% of the airflow and static pressure capabilities at lower noise. Sunon is usually a good source as well as nidec or delta.
Stay away from any maglev or sleeve/fluid dynamic bearings (sold under various marketing buzzwords) - those simply can't handle the higher rpms required (at least not for very long). For reliable high-rpm fans it's ball- or needle bearings, period.

You won't get those switches to livingroom-compatible sound levels. They dissipate quite a lot of heat and need to get rid of it. You can't haggle with physics.

 

[kapone]

In addition to what @sko said, the SX6036 has software fan speed control. At the lowest setting the stock fans will run between 4000-5000rpm depending on load.

That is certainly not silent, but it is not obnoxious either. My previous switch, the ICX-6610 was waaay worse. Had to cut open the chassis cover, install 120mm fans, fool around with faking the PWM/rpm signals...and it still wasn't as quiet as the SX-6036 at the lowest stock fan speeds.

For reference, my current SX6036 is almost completely full (32 of 36 ports connected) with DACs and just two optics, and it never goes above ~60w consumption or fan speeds above ~5100 or so.

 

[naptastic]

For reference, my current SX6036 is almost completely full (32 of 36 ports connected) with DACs and just two optics, and it never goes above ~60w consumption or fan speeds above ~5100 or so.

That's REALLY helpful. I've got the specs in front of me and there's no simple "with no cables plugged in, how much power does this draw?" answer. From the ATIS score I was expecting a figure closer to 80w.

My 6005's idle current was 40w when I got them, and they screamed like banshees. When I swapped the fans out, power draw went down to 20w. I'm only using one of them right now, and it's half-full of AOCs. Even with the wimpy Noctua fans, the optics only get warm to the touch.

I pulled the trigger on a 6036. I'm optimistic.

 

[nasbdh9]

If you don't care about QSFP temperature, you can remove all fan.

 

[naptastic]

It just came in and holy [CENSORED] this thing is loud!

Unfortunately it's DOA. (Fails to boot.) So I have no idea if I can lower the fan speeds yet. Time for console debugging.

(I hate console debugging and if I can't get this to boot... *sigh* why didn't I buy the protection plan...)

If ASIC and transceiver temperatures are close enough to ambient once I have the switch running 24/7, I'm definitely swapping the fans out.

Thanks everyone for the guidance. I still don't have "an answer" but y'all made the decision tree much more obvious.

 

[naptastic]

Update: It wasn't DOA; these switches just take a really long time to boot. Console access was necessary to get the latest firmware installed.

Setting the fans to run at 30% (the minimum before they go into hysteresis) makes the switch tolerable if it's in a closet with the door closed. Ambient doesn't exceed 74F / 23C and I'm using less than a third of the available ports. The highest temperature I've seen on a 40gbE transceiver was 38C.

The fans use a different connector. I think I'm not going to mess with it.