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Comment by sponaugle | Hacker News Reader

Those Mellanox cards are great and surprisingly inexpensive. I just put 4 of the dual QSFP+ cards in servers in my homelab and now have 80gb/s from each server. The Mellanox and Arista QSFP+ switches are also super cheap, and you can get QSFP+ DAC cables to do 40G.

In no way is 25G or 40G extreme. It is commodity low end in the real datacenter market.

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How noisy are the Mellanox and Arista switches you're using?

Asking because I'm looking for something suitable for a homelab (using Mellanox 40GbE cards) that's in the same room I tend to occupy during the day.

When I used very early Mellanox switches (years ago), they were only suitable only for datacenters. aka permanent super noisy jet engine mode

Their 1U 10Gb/s Infiniband switch is still the noisiest piece of equipment I ever made the mistake of buying! (!!!)

The arista switch's have an option to limit their max fan speeds, so they go from data centre deafening to as loud as a 1u server.

> as loud as a 1u server.

Depending on the 1u server, that's still super noisy. :(

Exactly lol.

Yea, it is impressive when they first turn on. You really start to think there is an aircraft overhead!

Indeed - They are loud. ;) You can slow the fan speed down some and that makes a difference, but they still produce a lot of fan noise:

If you listen in this video of my homelab: https://www.youtube.com/watch?v=-b3t37SIyBs

I would say that more than half of the total 'volume' is attributed to the three Arista switches. They are quite a bit louder than the Ciscos, and of course much louder than the Ubiquiti.

I certainly would not have one of these next to me in a work area.

On the other hand, they are the cheapest way to get 40G! With DAC cables it can be really inexpensive.

Thanks, that rules out the Arista option then. :)

I'm currently looking into the HP 5900AF-48XG-4QSFP+ (JC772A) switches, as they seem to be a good price/performance mix on Ebay. :)

My homelab is currently just a small setup with 4 boxes using 40GbE and a few others with 10GbE. Only one of them really needs the 40GbE though, the other's could be made 10GbE and not care. ;)

Random example of this switch:

https://www.networktigers.com/products/jc772a-hpe-5900af-48x...

Can't seem to find any info about noise levels though. :(

Found a data sheet with the acoustic info (https://s4u.com.ua/assets/files/hp%205900.pdf). 65.7-70.6 dB.

That's clearly not going to be workable. Damn.

Yea, a lot of them are pretty high flow due to the density of heat generated. Most are consuming 100-200watts, and that has to all come out as heat!

So - you could consider the Mikrotik - CRS326-24S+2Q+RM

It has 2 40G, and it is very quiet (I have one)

Thanks, that seems like the right kind of thing. :)

Nifty homelab by the way. :)

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