Can you connect two 10GBase-T computers together?

bmacklin

Member
Dec 10, 2013
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Forgive the imprecise wording in the title. What I am asking is if two computers each have a RJ-45 style 10GBase-T adapter, can they be connected together without the use of a router?

I'm intrigued by this mainly because it removes the need for a switch. I have two virtualized systems and all I need is the connection between them to be fast. I suppose I can try it out with my 1G ports and see if that works.

So can I get two of these:
671798-001 MNPA19-XTR 10GB MELLANOX CONNECTX-2 PCIe 10GB ETHERNET NIC

and a Sfp+ cable to connect them together without a router? Probably get a 10G connection for under $100?
 

MiniKnight

Well-Known Member
Mar 30, 2012
2,999
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NYC
That would work. I've found that I often want to expand so I might get a cheap 10Gb 2 port switch with some 1Gb ports. It'll cost an extra $200 or so, but you will be much happier when you want to add something else to that same network.
 

moto316

Member
Feb 23, 2014
56
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Yep it works, got a 1 foot cat6 cable connecting my two x9srh-7tf esxi6 hosts for 10Gb vMotion.
 

bmacklin

Member
Dec 10, 2013
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8
A follow up question: why is the MELLANOX CONNECTX-2 so much cheaper than say an Intel X540-T1 or T2?

Are there good driver support for both?

What cable do I need if I want to get two Mellanox cards and direct connect them together?
 

dswartz

Active Member
Jul 14, 2011
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A follow up question: why is the MELLANOX CONNECTX-2 so much cheaper than say an Intel X540-T1 or T2?

Are there good driver support for both?

What cable do I need if I want to get two Mellanox cards and direct connect them together?
A regular cable with QSFP connectors at both ends should work.
 

Keljian

Active Member
Sep 9, 2015
429
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Melbourne Australia
You should also be able to get a Chelsio t420-so-cr for not much more, and they are still officially supported with new drivers- they are 10gbit nics though with 7w draw
 

RTM

Active Member
Jan 26, 2014
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A follow up question: why is the MELLANOX CONNECTX-2 so much cheaper than say an Intel X540-T1 or T2?
Besides connectx-2 being fairly old, there is also not that much 10GBase-T hardware out there, like the x540's, so basic supply and demand kicks in.

However the fiber based Intel NICs, like the x520-da1 and x520-da2, are somewhat easier to get a good price on.
 

ziggygt

New Member
Jul 23, 2019
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It is great that the SFP+ can be direct connected between two computers. Some cards are becoming available with QSFP+/QSFP at a good price. There are some QSFP to 4x SFP+ cables. Can these be used to connect multiple (4) computers to the main server? Network traffic to other machines on 1Gb ethernet would be handled by the main server or any Win 10 machine with bridging SW that is built in.
 

Rand__

Well-Known Member
Mar 6, 2014
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No, breakout only works on a switch (that supports this functionality & has the port appropriately configured)
 

ziggygt

New Member
Jul 23, 2019
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Rand,
Thanks for the info. Is this because the QSFP+ to 4 x SFP+ cables do not support the cross over function. The switch needs to be configured for that function?. 1Gb ethernet RJ45 auto selects so not cross overs are needed. Can this be done with SFP+ cables? Do you think it is possible to re-wire the breakout cable ends to be a crossover cable.

Thanks for the Help. I Have a Dual 1366 Supermicro MB (win 10) and several HP Z400 systems (Win 10) I want to connect together for large fast file transfers to backup and access my FREENAS Z400.
 

Rand__

Well-Known Member
Mar 6, 2014
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I dont know why its not working card to card to be honest, never looked into it.
I don't think that fiddling with it is worth it considering the prices you are playing for 10 or 40g switches nowadays...
 
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ziggygt

New Member
Jul 23, 2019
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I dont know why its not working card to card to be honest, never looked into it.
I don't think that fiddling with it is worth it considering the prices you are playing for 10 or 40g switches nowadays...
Thanks. I’ll look at a switch
 

Rand__

Well-Known Member
Mar 6, 2014
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O/c QSFP 2 QSFP directly without switch will also work, just not with a 4:1 split.
Check the Brocade / Arista or Mellanox switches being referenced abundantly in the network section for options and potential deals :)