VIC 1280 vs VIC 1240 + Port Expander

[dani_bosch]

Hello,

What's the benefit of using VIC 1240 + Port Expander versus having a VIC 1280?? I don't see any.

Anybody has some inputs?

[Robert Burns]

Dani,

They are very similar.  The VIC 1240 is an mLOM (Modular LAN on Motherboard) only available on the M3 blades.  Natibvely it gives you 40Gbps BW per blade.  The Expander is a daughter card to complement the 1240 to expand it to 80Gbps. 

The 1280 VIC is our 2nd Generation VIC (based on our Sereno ASIC - First Gen was Palo-based)..  It works with any M1 & M2 server, wherease the 1240 is only availabe on M3 blades.  1280 VIC is capable of 80Gpbs natively. 

More informaiton & Comparision here:

http://www.cisco.com/en/US/products/ps10277/prod_models_comparison.html

Hope this helps.

Regards,.

Robert

[dani_bosch]

But that's why I'm asking: what's the point in using the VIC 1240 + Port Expander combination??

Using the VIC 1280 you get the same features plus you only occupy one slot, and still have one slot available...plus, VIC 1280 is cheaper than VIC 1240+Expander.

That's why I'm asking what woul be a reason to use VIC1240+Expander???

[Robert Burns]

The port expander add-on will not be as costly as the 1280 VIC.  The  blades do not have 2 Mezz slots - they have a single Mezz slot and mLOM.  You can't install a 1280 into an M3 expecting this will leave one  additional slot available.   If you're purchasing M3's blades with the  1240 mLOM, it makes more sense to just add-on the expander rather than  add a full 1280 VIC on top of it. The expander also uses a fraction or  power as the 1280 VIC. The most important difference is how the BW is  aggregated

The mLOM + Expander can provide up to 40Gbps of aggregated/Port Channeled BW per fabric.

The 1280 VIC can provide up to 20 Gbps of aggregated/Port Channeled BW per fabric.

The mLOM + 1280 can provide up to 2 x 20Gbps aggregated/Port Channeld BW per fabric.

So you get no BW increase on the blade by using a 1240+1280 rather than the 1240+Expander.  You do however get 2 adaptors per device for the host to manage, rather than 1.

Keep in mind, to achieve the max BW capacity to the blades you require 2nd GEN I/O Modules (2204/2208). 

Regards,

Robert

[dani_bosch]

a) Do you mean that if I order a B200M3 with a VIC 1280 in the mezzanine slot, I won't be able to add a 1240 VIC LoM on a later stage?

b) In the B-440M2, if I order two 1280 VICs, will I deliver 160 Gbps to the blade?

Thanks,

[Robert Burns · Accepted solution]

a) No. You can definately add the mLOM later, but understand the mLOM "slot" is for the mLOM only.  The Mezz slot is for the 1280 or other 3rd GEN adaptor.

b) Yes.  Now you have ther power!  Keep in mind the 160Gbp is burst max capacity.  You'd be hard pressed to find an application or end devices to sustain that throughput

Regards,

Robert

[dani_bosch]

Thanks Robert

[Robert Burns]

Did more investigation (sorry this is still very new), and using the 1280 alone (no mLOM) will only give 20Gbps to the blade, not 80.    I've corrected the above post also.

Full details including all scenarios are detailed clearly here:

http://www.cisco.com/en/US/prod/collateral/ps10265/ps10280/B200M3_SpecSheet.pdf

Regards,

Robert

[dani_bosch]

Robert, I see CCW doesn't allow me to configure a B-200M3 blade with only VIC 1280...it tells me I need to configure VIC 1240 as well...does that make any sense?? I thought one could perfectly configure VIC 1280 all alone...specially regarding the conversation we had in this thread in the past.

[Robert Burns]

Let me look into this and get back to you. 

What's the reasoning behind wanting the 1280 vs. the mLOM? One or the other will provide the exact same result, the difference being by using the mLOM you can free up the Mezz slot for another adapter.  The mLOM should also be far cheap an option than the 1280.

Robert

[dani_bosch]

Reason could be redistribution of spare mezzanines to spare blades in stock

[nicksousa]

https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/hw/blade-servers/B200M5.pdf

p. 45 for the B200 M5's mention that the mLOM is for the VIC only. The mezzanine slot can be used with a VIC, but also a port expander or storage device.

I found this thread when researching the mLOM/mezzanine connectors, and Robert's post doesn't appear correct (although this is a thread from 6 years ago, so I'm not entirely sure how much has changed in the meantime).