B-200M3 mezzanine slot

[dani_bosch]

Hello,

Spec sheet of B-200M3 says mezzanine slot is PCIe...but it doen't say what version...is it PCIe 3.0?

Also, I'd like to know whether there's any TOE capable mezzanine card for this blade. Reading the spec sheet doesn't look so...but still, wondering whether anyone has more details aboout it. In previous blades one could configure Boradcom TOE adapters...is this trend over?

Thanks,

[padramas]

Hello Dani,

VIC 1240 is x16-PCIe gen 2 card.

Table 1. Features and Benefits

http://www.cisco.com/en/US/prod/collateral/modules/ps10277/ps12377/data_sheet_c78-699459.html

B200 M3 technical spec sheet

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

says it supports CNA / NIC cards in the mezz slot.

I will check if B 200 M3 supports NIC M51KR-B Broadcom BCM57711 Network Adapter ( capable of TOE and iSCSI offload ) or not.

Can you please elaborate the need for TOE ?

Padma

[dani_bosch]

The need for TOE is to accelerate iSCSI traffic.

You told me VIC 1240 is PCIe Gen 2....but my question was more related to the slot itself, rather than the card we can plug in. Customer is asking me whether the slot is PCIe 3.0 capable

Thanks,

[Robert Burns]

Dani,

The slots are PCI 3.0 capable (as well as backwards compatibile with 2.0 & 1.0).

In regards to the iSCSI TOE capable cards, Broadcom is the only vendor that has a TOE.  We've done extensive tesing with the Cisco VIC (Palo, 1240 mLOM and 1280 - no TOE) and Broadcom (TOE) and there's little difference in performance between the two cards in relation to iSCSI performance..   Todays CPU's are so powerful there's virtual no hit for calculations TCP checksums etc performed in SW.  Back 5 years ago, this was a slight different story where the offloading of TCP functions did make a difference.  The Cisco VIC was designed from the ground up well after TOE capable cards where around.  I asked the same questions to our engineering teams why wouldn't be include this with our VIC.  Our Palo & Serrano (Gen 1 and Gen 2 VICs) ASICs and Intel processor advances are making TOE requirements virtually non-existent.

Regards,

Robert

[dani_bosch]

Thanks Robert. Just to clearify it: I understand out of your comments, that TOE is not needed thanks to Intel CPUs, rather than VIC ASICs, right? So, the big difference is NOT in the new ASICs of the VIC (Cisco feature) but in the power of the new Xeons (Intel feature).

Am I correct?

[Robert Burns · Accepted solution]

It's a combination of both.  Non TOE-enabled NICs rely on extra processor cycles to accomplish what a TOE offloads, and with the multi-core systems today, this overhead is minimal.  The Palo/Sereno ASIC contribute to improved performance due to the buffering & multi-receive queues improving general networking & storage performance against competing CNAs. 

Robert

[dani_bosch]

Robert, does this TOE argument also apply to Large Send Offload?

[Robert Burns]

Yes.  TOE function includes offloading LSO/LRO as well as all other TCP functions.

There's a good article that might help clear up the benefits vs. performance factors:http://searchstoragechannel.techtarget.com/feature/TCP-IP-offload-engine-TOE-cards

http://searchstoragechannel.techtarget.com/feature/TCP-IP-offload-engine-TOE-cards

Regards,

Robert

[dani_bosch]

Thanks a lot Robert.

Also I'd like to ask you: is there any way to connect a GPU card in the B-200M3? The mezzanine slot is PCIe but I guess that doesn't mean one can plug any PCIe card there, right?

[Robert Burns · Accepted solution]

No.  The B200 M3 mezz slot isn't for just any PCIe device, the form factor will accept only Cisco provided adapters.   We don't currently have any GPU offereing yet for B-Series, but we do have a tentative roadmap for them in the C-Series.

This could change one day for blades though.

Regards,

Robert

[dani_bosch]

Got it.

Thanks a lot for your help Robert!

[dani_bosch]

Hello Robert, sorry to bother you again...just another question:

Is there any white paper or official paper out there that states what you just told me about the obsolescence of the TOE feature in the industry due to today's CPUs? Obviously I trust what you just said, but my customer would like some official documents in this regard...

[Robert Burns]

There's no such Cisco docs I know of.  The two links I pasted above are the closest I've seen.  A vendor will not state the obsolence of a technology that is not their own, such as TOE's.  The best we can do is report on our own performance verse other adapters.

I'll check to see if we have any such performance whitepapers and get back to you.

Regards,

Robert