Needing more 10gb ports on 6610–DAC or MTP approach?

[safado]

I screwed that up and posted early. Here’s the context:

I have a Brocade 6610 that I’m getting full on the 8x SFP+ ports so I’m thinking of utilizing the QSFP ports on the back for a 4x 10gb breakout.
I’ve noticed there are DAC cables like below that seem to have transceivers already attached and are the cheap option. All my equipment is in the same rack but I’m using various NICs like the ConnectX-3 and variants of the X520 currently with SFP’s and MM fiber.

As QSFP is “new” to me what I don’t understand is it better to use a DAC cable or buy a QSFP for the brocade and then a MTP to 4 LC cable with the different SFP’s like the other link below?

Seems like the DAC cable is the cheap and quick way to go but I worry about compatibility between the various cards.

What’s the best practice here and recommended approach?

Thanks!

Customized 40G QSFP+ to 4x10G SFP+ Passive Breakout DAC Cable - FS.com

Check 40G to 10G Passive Breakout Direct Attach Cable data sheet (DAC Cable, QSFP+ to 4 SFP+, Customized length) and price list on FS.COM, Lifetime Warranty!

www.fs.com

1m (3ft) MTP-8 LC OM4 50/125 MTP® Breakout Cable, OFNP - FS.com

Buy 1m (3ft) MTP®/MPO fan-out fiber patch cord MTP® Female to 4 LC UPC Duplex 8-Fiber OM4 Multimode Harness Cable, Polarity B, Elite, OFNP at reliable supplier.

www.fs.com

 

[Sean Ho]

Cisco Systems Qsfp-4sfp10g-cu1m QSFP to 4xsfp10g Passive Copperperp Splitter 1m for sale online | eBay

Find many great new & used options and get the best deals for Cisco Systems Qsfp-4sfp10g-cu1m QSFP to 4xsfp10g Passive Copperperp Splitter 1m at the best online prices at eBay! Free shipping for many products!

www.ebay.com

JH834A HP Arista QSFP28 4x25G SFP+ 2m DAC Cable | eBay

Find many great new & used options and get the best deals for JH834A HP Arista QSFP28 4x25G SFP+ 2m DAC Cable at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[safado]

Thank you!! You responded so fast I’m afraid you didn’t see my initial edit and additional info about DAC vs MTP. Will I run into any compatibility issues with DAC across different NICs? Thanks!

 

[Sean Ho]

DAC, MTP breakout (plus optics), AOC, all are equivalent and will get the job done. DAC are cheapest and lowest power/heat, but length limited to about 10m (hard to find anything over 3m on ebay). Perfect for within the rack. The cabling is thicker and heavier than fiber, obviously; also, thicker DACs aren't necessarily better or sturdier.

Regarding SFP compatibility, Brocade and Mellanox will be fine; Intel does check but ixgbe.ko option allow_any_sfp is sufficient on Linux; an OS-agnostic fix requires modding the EEPROM: https://forums.servethehome.com/ind...-eeprom-to-unlock-all-sfp-transceivers.24634/

 

[safado]

DAC, MTP breakout (plus optics), AOC, all are equivalent and will get the job done. DAC are cheapest and lowest power/heat, but length limited to about 10m (hard to find anything over 3m on ebay). Perfect for within the rack. The cabling is thicker and heavier than fiber, obviously; also, thicker DACs aren't necessarily better or sturdier.

Regarding SFP compatibility, Brocade and Mellanox will be fine; Intel does check but ixgbe.ko option allow_any_sfp is sufficient on Linux; an OS-agnostic fix requires modding the EEPROM: https://forums.servethehome.com/ind...-eeprom-to-unlock-all-sfp-transceivers.24634/

Thank you!! This is extremely helpful. Really appreciate you taking the time to help and offer advice. Thanks!