Thanks Michael,
Thanks for all of the information. Regarding your final paragraph, you
mentioned that the 64 Gb/s could be handled on one 100 Gb link. However,
that seems at odds with the following statement in the UHD manual in the X410
section about FPGA types
<https://files.ettus.com/manual/page_usrp_x4xx.html#x4xx_updating_fpga_types>
- CG_400: 400 MHz analog bandwidth streaming per channel between the
X4x0 and an external host computer. The current implementation requires
dual 100 GbE connections for 4 full-duplex channels or a single 100 GbE
connection for 2 full-duplex channels.
Do you think that this statement in the UHD manual is a mistake? This is
the statement that made me think that I needed two 100Gb links even though
the 4 channels at 500 MS/s is aggregate 64Gb/s. If only one link is truly
needed, then I can feel more confident purchasing an E810.
Rob
On Wed, Mar 26, 2025 at 3:53 PM Michael Dickens <michael.dick...@ettus.com>
wrote:
> Hey Rob! Great questions. Here's way too much information taken from
> internal notes I have on the subject, to help you process all of this :)
> {{{
> E810 QCDA2 provides 100 Gb aggregate between both ports. Dual port to USRP
> is not recommended since UHD doesn't "know" this limitation.
>
> E810 2QCAD2 provides 2 bifurcated 100 Gb links, so can do 200 Gb
> aggregate. I -think- one has to tell BIOS / OS about this bifurcation to
> get the NIC fully working. I don't have one to test out.
>
> There are now newer Intel E82* NICs. I don't know their capabilities.
>
> Any of the Intel E8* NICs can be configured in various ways, the most
> relevant for USRPs are:
> * 2x1x100 : 2 ports, each hosting 1 virtual link at 100 Gb
> * 100 : 1 port with a single virtual link at 100 Gb
> * 8x10 (formerly 2x4x10 : 2 ports, each hosting 4 virtual link at 10 Gb
> each
> {{{
> $ sudo ./epct64e -get -nic 1
> Ethernet Port Configuration Tool
> EPCT version: v1.42.24.04
> Copyright 2019 - 2024 Intel Corporation.
>
> Available Port Options:
> ==========================================================================
> Port Quad 0 Quad 1
> Option Option (Gbps) L0 L1 L2 L3 L4 L5 L6 L7
> ======= ============================= ================ ================
> 2x1x100 -> 100 - - - 100 - - -
> 2x50 -> 50 - 50 - - - - -
> 4x25 -> 25 25 25 25 - - - -
> 2x2x25 -> 25 25 - - 25 25 - -
> Active 8x10 -> 10 10 10 10 10 10 10 10
> 100 -> 100 - - - - - - -
> }}}
>
> FWIW: We're had a number of customers with E810 CQDA2 issues recently. My
> current belief is that the NIC (NVM) and OS drivers do not play nicely
> together & hence updating both to the latest is needed to get everything
> working properly.
>
> Intel E8* NICs used the ICE driver, which is in active development & works
> pretty well overall. ICE drivers -do not- work seamlessly with DPDK unlike
> Mellanox ones. It's easy to create a script to do the driver binding & link
> stuff both down and up, but this can be very confusing for people not used
> to taking down a link and rebinding the driver & then the reverse to get it
> back working in the system again.
>
> The Mellanox drivers & hardware use a little less CPU time than the Intel
> ones, so a little better single-core performance — which helps when using
> DPDK and doing max data throughput.
>
> Yes, 500 GS/s on 4 channels (2 GS/s aggregate) is 64 Gb/s and thus well
> within the capabilities of a single 100 Gb port on either NIC ... That's
> fine for an X410. For an X440 we double that to 4 GS/s aggregate, which
> clearly requires 2x 100 Gb links. For this use-case the Mellanox NICs are
> the way to go.
> }}}
>
> On Tue, Mar 25, 2025 at 3:53 PM Rob Kossler via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> Hi,
>> I am in the process of purchasing a 100Gb NIC for use with the X410 and
>> have seen documentation and previous posts indicating that the ConnectX
>> NICs are preferred. But I did note in the DPDK knowledge base article that
>> the Intel E810 could also work. I prefer the E810 because it seems to be
>> less expensive and can be configured for 4x10Gb, but I don't want to create
>> a headache for myself. Let me know if you have had success or issues with
>> the E810 using a 100Gb link (or two 100Gb links) to the X410.
>>
>> I am also confused about the E810 which comes in a couple of 100Gb
>> models: CQDA2 and 2CQDA2, where they both have two 100Gb QSFP28 ports, but
>> the former can only handle aggregate 100Gb whereas the latter can handle
>> aggregate 200Gb. My confusion is "why does it matter for the X410?". With
>> 4 channels at 500 MS/s, the aggregate bit rate is only 64Gb/s so why does
>> it matter if the E810 CQDA2 only supports aggregate 100Gb? It seems to me
>> that either model supports the maximum rate of the X410.
>>
>> Thanks.
>> Rob
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>>
>
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