Do you buy optical transceivers from ebay?

[i386]

QDR/40gbe

 

[_alex]

ok, thanks. i really wonder what transceivers would do fdr then, couldn't find too much about compatibility.

 

[i386]

Finally good news: the mellanox coded qsfp+ transceivers from fs.com work with the proper fibers.

It's stupid that I can get used cisco qsfp+ transceivers from ebay to work on another branded switch (arista) , but not on the network adapters ._.

Edit: food -> good

I'm not sure what I did but the cisco qsfp+ transceivers work on the cx-3 now and I can get a 40gbe/qdr link.
The infiniband tool can even show some information like the temperature of the transceiver...

Edit:
Setups for the transceiver tests
40gbe: host a > switch -> host b
qdr ib: host > host b

 

[Adamr]

I buy the used Cisco GLC-SX-MM transcievers for $2 a pop on ebay with free shipping I don't know how this guy makes any money but I have never had a problem with the 10+ I have purchased