Mellanox QSFP to SFP+ Adapter $10

Sleyk

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Mar 25, 2016
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I have a question about these. I see that it allows you to use SFP+ transceivers in a QSFP slot. Does this allow you to obtain 40Gbps through your older LC-LC multimode fiber? Should work right? As long as it is connected to a 40Gbp adapter? Or will it downclock to 10Gbps through this adapter?
 
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Evan

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Jan 6, 2016
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That's on a 100gbps adapter though, not a 40gb right?
25G SFP (100G QSFP28 port)
This is just an adapter, you still need to obey the ASIC behind the port limitations and the SFP+ you have inserted. Meaning a 10G-SR won’t suddenly do 25G.
If the port/asic supports I have been crazy enough to use GLC-T in a 100G capable port (some maybe even most 40/100g ports will run at 10/25 or even 1G with the appropriate adapter)
 
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Sleyk

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Mar 25, 2016
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Agreed. I was just clarifying for @Sleyk as they were talking about a 40gb adapter specifically.
Yeah, was wondering about the 40Gb adapters. I wanted to keep my existing fiber and I wondered if OM3 was capable of going to 40Gbps with these adapters, but I suppose no.

Im starting to wonder now about maybe going to 25Gb? I know its a different protocol though.

Damn, I wish we had one fiber standard.
 

Evan

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Jan 6, 2016
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OM3 will support 40G bidi to 100 meters,
OM4 extends that to 150 meters.
 
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BeTeP

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Mar 23, 2019
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If your existing OM3 is just 2 LC terminated fiber strands (you would probably not be asking this question if your fiber was MPO terminated) and you want to get 40Gbps - you would need 2 QSFP+ 40G BiDi transceivers at $100+ ea per link.
 

Evan

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Jan 6, 2016
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40G BiDi don’t really cost $100 do they ?
Looks at ebay... not that far off, $40 and up each.
 

BeTeP

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Mar 23, 2019
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I see one lot at $55ea, another at $78ea and everything else is $85+. Still too expensive for my blood (for home use). But it is nice to see the price going down since I checked last time.
 

Sleyk

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Mar 25, 2016
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If your existing OM3 is just 2 LC terminated fiber strands (you would probably not be asking this question if your fiber was MPO terminated) and you want to get 40Gbps - you would need 2 QSFP+ 40G BiDi transceivers at $100+ ea per link.
Ouch my wallet cries, brother!