How to cable CX7 (OSFP) to Mellanox MSN4600 QSFP28

[kgcdctx]

Got new GH200 with CX7 in a rack with an older switch temporarily. But I can’t figure out how to cable this…

I can’t find an OSFP to 4-port QSFP28 breakout except one for an absurd $2500.

I need 1.5m and passive/DAC etc.

Help?

 

[kgcdctx]

Can’t be done. Had to downshift to Cx6.

 

[jpmomo]

were you trying to fanout from the cx7 to a 100G switch? As far as I know, the cx7s do not fanout yet. when they do (maybe July) they will probably need a DR4 to 4 x DR1. Which DAC did you find that would go from an OSFP cx7 (needs to be flat top) to 4 x 100 (qsfp28)?

 

[kgcdctx]

I found some outrageously expensive thing that I didn’t buy.

What’s happening in July?

For now I bought new CX7 variants with cages compatible with my switch. Supermicro really screwed me over here.

 

[jpmomo]

Nvidia may introduce new firmware that supports fanout capabilities on some cx7 nics

 

[kgcdctx]

Given I just spent 2 weeks with SMC support trying to fix my issue, and I buy from them because of their Nvidia relationship, this is disappointing!

Thx!

 

[jpmomo]

I have been dealing with these cx7s for a few years now and it is still frustrating

 

[clover@modulenets]

You can use 2 units of 400G OSFP SR4(Nvidia's MMA4Z00-NS400) connecting with a MPO12 cable. Our company have the 400G OSFP SR4(both the hardware and software are the same with original ones) FOR Nvidia for supply and verified in CX-7 newest ISO already. The website is www.modulenets.com

 

[necr]

Can’t be done. Had to downshift to Cx6.

for those having the same problem - there's now a DAC that can do this, see the OSFP experience thread