Solved! Switch (Arista) And NIC (Mellanox) Compatibility Question

Jan 13, 2022
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Hello,

My company plans on building a system with the following NIC: Mellanox MCX653106A-HDAT


...and I was wondering whether it would work with the following switch: Arista 7050SX-72Q

https://www.arista.com/assets/data/pdf/Datasheets/7050SX-128_64_Datasheet.pdf

Arista.png

Even though the switch is older (and can't handle the high throughput of the Mellanox), the plan is to eventually replace the Arista (but for now, just use the Mellanox at a lower throughput),

I assume the Arista and the Mellanox should be able to auto-negotiate with one another, but one of the Engineers on my team mentioned that QSFP+ (on the Arista) couldn't work with QSFP56 (on the Mellanox).

In case the Mellanox doesn't work with the Arista, could someone recommend the highest throughput NIC that can work with the Arista?

Any help would be greatly appreciated.

Thank you,
Nelson
 

Tech Junky

Senior member
Jan 27, 2022
840
271
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  • Deleted by JackMDS
  • Reason: Double post
1644806406765.png

Looks like there's a limit to how much you can push through the Arista compared to the Mellanox.

Mellanox up to 200gbps/port
1644806595390.png
Arisa up to 10gbps/port SFP+ or 40gbps/port QSFP

I would probably shoot for 2 x 40gbps bundled into a port-channel / LACP bundle to get the most out of it.
 
Jan 13, 2022
52
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View attachment 57409

Looks like there's a limit to how much you can push through the Arista compared to the Mellanox.

Mellanox up to 200gbps/port
View attachment 57410
Arisa up to 10gbps/port SFP+ or 40gbps/port QSFP

I would probably shoot for 2 x 40gbps bundled into a port-channel / LACP bundle to get the most out of it.
Hello Tech Junky,

Understood (thank you for the clarification).

Just to be certain though, in your post you mentioned looking for NIC's with QSFP ports.

Did you really mean QSFP+, or should I just look for QSFP (as the documentation above seems to mention QSFP+ ports)?

Thank you,
Nelson
 

Tech Junky

Senior member
Jan 27, 2022
840
271
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I just left off the + since most new cards are automatically +

Now POE on the other hand can be + or ++ depending on the power demand of the endpoint.

The main consideration is both sides can meet the same speed 40<>40
 
Jan 13, 2022
52
1
11
I just left off the + since most new cards are automatically +

Now POE on the other hand can be + or ++ depending on the power demand of the endpoint.

The main consideration is both sides can meet the same speed 40<>40
Hello Tech Junky (or anyone else),

I found two cards which should work, between the following two cards: St. Helens 200G4Q-XL


...or: PE31640G4QI71 Server Adapter


...do you prefer/recommend a specific card?

Thank you once again for all your help,
Nelson
 

Tech Junky

Senior member
Jan 27, 2022
840
271
96
If you're planning on changing the switch then stick with the Mellanox card. It will do the 40gbps speed now and allow for 200gbps per port down the road with the new switch if it supports the speed.

These days though most any NIC should be up to the job unless you spot a ton of reviews saying it's not. I tend to aim for the cheapest option personally I don't see the need to pay $400 for an Intel based NIC when I can get a QNAP for 50% less that does the job just as well.

1644852059611.png

I've used Startech devices before and they work great in niche setups when no one else carries what you're looking for. $650 sounds a whole lo better than $1200-$1800 for the same functionality. Diving into pricing though there's probably a better deal to be found somewhere.

$500

$900

I'm using QXG-5G4T-111C for my server setup w/ NAS in Raid 10 because it allows for enough overhead and isn't a bottleneck for the array @ 400MB/s + additional traffic while moving files around. I've been using it for about a year now and it's been flawless in Linux. The only issue I've come across is certain kernel versions don't play well with it on occasion as I tend to upgrade often for the security patches as this box is my router.
 

KentState

Diamond Member
Oct 19, 2001
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QSFP+ is the old 40G standard and not future proof. You would want to look at something like QSF28. If you do go the older route, buy used since companies are dumping them for newer, more efficient technologies. I have picked up a ton of Chelsio dual port QSFP+ for home use at home. Even the Arista swtiches can be found for under $700 on ebay in 16 and 32 port configurations. If you need 10Gbe, they make fan out cables as well.
 

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