Compatible active FS SFP+ DAC for Mellanox Connectx-2/3 and possibly TP-Link switch

anomaly

Active Member
Jan 8, 2018
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Hi!

I need a 10 meter active SFP+ DAC to connect my workstation peer to peer to a server with Mellanox Connectx-2 cards. I might get a TP Link SFP+ enabled switch in the future... so compatibility would be nice to have.

Since the cables run for 81 USD new, which ones should be the most compatible? Generic? Cisco? Intel?

Thanks!
 

i386

Well-Known Member
Mar 18, 2016
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I don't have active dacs, but optical transceivers.
I think for 10gbe(sfp+) mellanox cards don't care which branded dacs (active OR passive) you use, the switch will show a warning in the log about an unsupported cable/transceiver but will work.
 

anomaly

Active Member
Jan 8, 2018
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Thank you all for the answers, this is good news. I hope then I can also expect little trouble with the TP Link switch in the future.
I will need at least 10m though. What would be the most sensible spot to look for these? eBay?
 

I_D

Member
Aug 3, 2017
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I need a 10 meter active SFP+ DAC to connect my workstation peer to peer to a server with Mellanox Connectx-2 cards. I might get a TP Link SFP+ enabled switch in the future.
Since the cables run for 81 USD new, which ones should be the most compatible? Generic? Cisco? Intel?
I own a TP-Link T1700G-28TQ. When I received it, I tried all the DAC cables I have, about 24 different ones from fs.com, both generic and cisco coded ones, as well as all sorts of authentic vendor dac cables from dell, hp, cisco, etc.
I also use Mellanox ConnectX2 cards as well as some Chelsio dualport cards.
They all work fine, but they are passive dacs, I do not have any active DAC cables (and you will need active if you want to use a DAC for a distance that long!)

However, if your card and switch have SFP+ slots, why not just get transceivers and plug in an LC to LC multimode fiber?
That should be a lot cheaper than those long active DAC cables.
Regular fiber LC to LC cables are sold in all types and colors, even bend-resistant and armored versions are available if you need them in your house. (I just use the cheapest kind and run them in a small pvc pipe I have for my cables)
DAC's are generally cheapest with FS.com but LC to LC I find cheapest on ebay.

Here is a quick ebay shopping list to save you over 50% in costs:

253409698651 -> 1x LC to LC 10m cable 10,79 USD
202136661138 -> 2x 10G SFP+ Finisar transceiver 27,98 USD
TOTAL COST: 38,77 USD (incl. shipping)


Word of advice, do not buy the TP-Link T1700G-28TQ like I did if it's just to get some extra SFP+ slots.
Not that I have complaints about the TP-Link, but I wish that Mikrotik had released their CRS317-1G-16S+RM, then I would have bought that instead.
At only about 150 euro more, I would have had 12 more ports.
 
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