Thanks again for the response and information. I'm seeing pretty much what you are. If I make a gnuradio flowgraph with a UHD:Usrp_Source connected to a Null_Sink, I can set the sample rate to 4MHz without overflows. With a sample rate of 5MHz, I see "OOOOO" repeating in the console. So the maximum throughput I am seeing is about 32*4MHz = 128Mbps. As you said, it is definitely higher than the 10Mbps reported by ethtool, but not as high as I need. Unfortunately, I don't have a 10Gbit interface available.
I started out with the SFP connected to a switch, through our company's network, and to my development machine. I thought maybe the extra infrastructure was the issue, even though an iperf throughput test (from the management port to my computer) showed about 480Mbps. I assumed the SFP port to my computer would allow for a similar throughput through the network. Anyhow, I ended up hooking the SFP directly to a 1gbps Ethernet port on my computer (taking the switch and network out of the loop). This made no difference in the throughput I can achieve. It's still a little over 100Mbps. If you have any ideas what the throughput issue could be, I would greatly appreciate it. We really need to run at higher sample rates than I'm currently able to do. Thanks, Jim ________________________________ From: Michael Dickens <michael.dick...@ettus.com> Sent: Wednesday, December 9, 2020 1:15 PM To: Jim Palladino <j...@gardettoengineering.com> Cc: usrp-users@lists.ettus.com <usrp-users@lists.ettus.com> Subject: Re: [USRP-users] E320 SFP speed/duplex question Hi Jim - Yes you are correct in the E320 FPGA image options: 1G, XG, and AA. I booted up my E320 to verify; forgot that there is just a single SFP+ port on the E320 ... I've been working with X310's and N310's for a while now, both of which have 2 SFP+ ports! Since I'm on my E320, I tried out the XG and 1G FPGA images. Using "ethtool" as you noted, the XG image shows "Speed" of 10000Mb/s, while the 1G image shows 10Mb/s ... even though as you note the link modes are just "1000baseT/Half 1000baseT/Full". Strange! Using the "1G" FPGA image, I can sustain 2x2 MIMO at 1.45 M-Samples/second (but no 2 MS/s), with the wire format being SC16 (4 bytes per sample) ... that's 92.8 Mb/s bidirectional .. so, clearly more than the 10 Mb/s noted by "ethtool" ... much closer to 100 Mb/s link speed expect throughput (about 90% of theoretical) but nowhere near 1 Gb/s! Admittedly I had to move to a 1Gb link via a possibly-ill-configured-switch to get this to work at all, since my internal USRP testing network is a mix of SFP+ 10 Gb and QSFP+ 40 Gb links. Using the "XG" FPGA image, I can sustain 2x2 MIMO at 60+ MS/s, which is good. I'm not sure what's going on with the 1G FPGA image, but if the link works well enough for your needs then that's the bottom line here! I believe the following is correct ... and I'm sure if I'm off a bit then someone will chime in to correct me :) The Aurora FPGA image is built with the free Xilinx Aurora FPGA-IP, allowing for FPGA to FPGA high speed serial link. Think of it as a link-layer transport protocol, where one needs to create the higher-layer protocols to do actual data transport. Aurora was used in the DARPA SC2 Colosseum for high-speed transfer between USRPs and other FPGA processing devices. Aurora removes the internet protocol layers, providing direct access to the physical networking interface: bits in, bits out ... No ethernet, IP, UDP handling! We provide a little information on the UHD manual for the E320 about Aurora: * < https://files.ettus.com/manual/page_usrp_e3xx.html#e320_fpga_flavours<https://urldefense.proofpoint.com/v2/url?u=https-3A__files.ettus.com_manual_page-5Fusrp-5Fe3xx.html-23e320-5Ffpga-5Fflavours&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=XUEEtUEfpaAEGxRI-WGuqHauOvsPdD2NZkfwDnwpYx0&m=7N8gAH6vgMzO-NwRZFhDG4KfKuV1TD3bECwVc0phexQ&s=XOLlOog92yheS2apHdPQC58eepUR3d9r8QEXmeUcCO0&e=> > {{{ The Aurora image can be used to run BISTs on the SFP. }}} * < https://files.ettus.com/manual/page_usrp_e3xx.html#e3xx_troubleshooting_bist<https://urldefense.proofpoint.com/v2/url?u=https-3A__files.ettus.com_manual_page-5Fusrp-5Fe3xx.html-23e3xx-5Ftroubleshooting-5Fbist&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=XUEEtUEfpaAEGxRI-WGuqHauOvsPdD2NZkfwDnwpYx0&m=7N8gAH6vgMzO-NwRZFhDG4KfKuV1TD3bECwVc0phexQ&s=V3o5ZjN6FSwDrC7ogJcxLGvTkw-vhNq3-xMYd3Eh1yk&e=> > {{{ E320 Built-in Self-Test (BiST) The E320 series devices have a built-in self-test that can be used to verify the hardware. It is not automatically run, but it can be invoked anytime by running the e320_bist executable. Calling e320_bist -h will list the available options. Tests can be run by specifying their name, e.g. e320_bist gpsdo will test the functionality of the GPSDO. Calling e320_bist standard will run a standard set of tests, verifying some base peripherals such as the RTC, the fan and temperature sensors, etc. Some tests require special hardware connected. For example, for the sfp_loopback tests, a loopback module must be plugged into the SFP+. Tests may also load different FPGA images, if required. The aforementioned SFP tests will load the Aurora FPGA image and use Aurora to run the BER tests on the SFP port. This is particularly relevant if either a custom image was loaded, or if there is an active SSH or other connection coming in via the SFP+ ports. }}} I hope this is useful! - MLD On Wed, Dec 9, 2020 at 11:25 AM Jim Palladino <j...@gardettoengineering.com<mailto:j...@gardettoengineering.com>> wrote: Hi Michael, Thanks for the response. I did load the FPGA image again using "1G". My options are "1G", "XG", "AA". I still have the issue where linux/ethtool is still reporting a 10Mbps / half-duplex link on sfp0. Again, I'm able to stream data, so maybe things are working fine. Thanks, Jim ________________________________ From: Michael Dickens <michael.dick...@ettus.com<mailto:michael.dick...@ettus.com>> Sent: Wednesday, December 9, 2020 11:07 AM To: Jim Palladino <j...@gardettoengineering.com<mailto:j...@gardettoengineering.com>> Cc: usrp-users@lists.ettus.com<mailto:usrp-users@lists.ettus.com> <usrp-users@lists.ettus.com<mailto:usrp-users@lists.ettus.com>> Subject: Re: [USRP-users] E320 SFP speed/duplex question Hi Jim - Just for completion: Try loading the "HG" image -- again if necessary: 1 Gb on SFP+ port 0 and 10 Gb on SFP+ port 1. Regardless of whatever Linux / ifconfig / ethtool shows, the SFP+-based networking will not work if the link speeds are not met on both ends. All USRPs will set the correct speed via the FPGA: 1 Gb or 10 Gb, depending on the FPGA image used. The only way to get different link speeds is a different FPGA image. Once configured on both ends, if data transport is working then, if Linux / ifconfig / ethtool still shows 10 Gb link speed then, yes, something is off with those tools -- but, clearly the USRP is working as desired & that's the bottom line here hopefully! - MLD On Wed, Dec 9, 2020 at 9:44 AM Jim Palladino via USRP-users <usrp-users@lists.ettus.com<mailto:usrp-users@lists.ettus.com>> wrote: Hello, I just setup an E320 with a 1Gbps SFP. I've updated the filesystem, FPGA load (with the "1G" build"), etc and am using UHD 4.0. uhd_usrp_probe seems happy, and I created a gnuradio flowgraph and streamed samples ok. I did not test throughput, though. What concerns me is that when I connect to the E320 via serial console and boot, I see this: [ 23.592701] nixge 40000000.ethernet sfp0: Link is Up - 10Mbps/Half - flow control off [ 23.733169] nixge 40020000.ethernet int0: Link is Up - 10Mbps/Half - flow control off If I check with ethtool on the E320, I see: ---------------------------- Settings for sfp0: Supported ports: [ TP MII ] Supported link modes: 1000baseT/Half 1000baseT/Full Supported pause frame use: Symmetric Receive-only Supports auto-negotiation: No Supported FEC modes: Not reported Advertised link modes: 1000baseT/Half 1000baseT/Full Advertised pause frame use: Symmetric Receive-only Advertised auto-negotiation: No Advertised FEC modes: Not reported Speed: 10Mb/s Duplex: Half Port: MII PHYAD: 0 Transceiver: internal Auto-negotiation: off Link detected: yes ------------------------------------ I know that the SFP is directly connected to the FPGA, and the load I put on the FPGA is for 1gbps. Is the ethtool reported speed of 10Mbps and duplex=half even meaningful? By the way, our network switch that the sfp is ultimately connected to shows a 1gbps/full duplex connection on that port. I'm just a little confused with what is happening between linux/ethtool/ARM vs the FPGA SFP connection and whether or not I actually have a speed/duplex problem. Thanks, Jim _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com<mailto:USRP-users@lists.ettus.com> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.ettus.com_mailman_listinfo_usrp-2Dusers-5Flists.ettus.com&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=XUEEtUEfpaAEGxRI-WGuqHauOvsPdD2NZkfwDnwpYx0&m=h6gfUd4_-1RcS5UAfGAHCk5wNYVY066vaNcSpuMyVKs&s=v42cqkoKiKIWGSBTjv2y2lowcm0jBCLsg4iGVWB31w8&e=>
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