[USRP-users] X300 underflows with tx_rate 100Msps

Nate Temple nate.temple at ettus.com
Mon Nov 25 15:24:57 EST 2019


Hi Voonna,

What is your CPU frequency?

What kind of NIC are you using?

If your NIC supports DPDK, I would recommend trying to use the DPDK
transport, but you will need to update to UHD 3.14.1.1 to support DPDK with
the X310.


https://files.ettus.com/manual/page_dpdk.html

Regards,
Nate Temple

On Thu, Nov 21, 2019 at 9:35 AM voonna santosh via USRP-users <
usrp-users at lists.ettus.com> wrote:

> Hi Michael,
>     I am experiencing lots of underflows when I use benchmark_rate example
> app. Following is the configuration:
>
> Host processor    : Intel® Xeon® Processor D-1500 System on Chip (SoC)
> Host OS: Centos 7
> UHD: release_003_010_001_000
> SDR HW: X300 with UBX-160 (Calibration done as documented)
> Eth link: SFP
>  - Maximum socket buffer sizes (wmem_max, rmem_max)
>  - MTU 9000
>  - Tx/Rx descriptors (sudo ethtool -G <interface> tx 4096 rx 4096)
>  - thread priority set to 1
> CPU usage: Only two CPUs are being used, but rest of the cores are free
> and the host is headless(No CPU consuming apps).
>
>   If I test rx_rate with 200Msps, it works well. But when I use tx_rate
> with 100Msps, I could see lots of underflows (Us).
>
> ./benchmark_rate --args="addr=192.168.40.2" --tx_rate=100e6
> --channels="0" --duration 200
> linux; GNU C++ version 4.8.5 20150623 (Red Hat 4.8.5-39); Boost_105800;
> UHD_003.010.001.HEAD-0-g929e3b32
>
>
> Creating the usrp device with: addr=192.168.40.2...
> -- X300 initialization sequence...
> -- Determining maximum frame size... 8000 bytes.
> -- Setup basic communication...
> -- Loading values from EEPROM...
> -- Setup RF frontend clocking...
> -- Radio 1x clock:200
> -- Detecting internal GPSDO.... Found an internal GPSDO: LC_XO, Firmware
> Rev 0.929b
> -- [DMA FIFO] Running BIST for FIFO 0... pass (Throughput: 1179.5MB/s)
> -- [DMA FIFO] Running BIST for FIFO 1... pass (Throughput: 1184.4MB/s)
> -- [RFNoC Radio] Performing register loopback test... pass
> -- [RFNoC Radio] Performing register loopback test... pass
> -- [RFNoC Radio] Performing register loopback test... pass
> -- [RFNoC Radio] Performing register loopback test... pass
> -- Performing timer loopback test... pass
> -- Performing timer loopback test... pass
> Using Device: Single USRP:
>   Device: X-Series Device
>   Mboard 0: X300
>   RX Channel: 0
>     RX DSP: 0
>     RX Dboard: A
>     RX Subdev: UBX RX
>   RX Channel: 1
>     RX DSP: 0
>     RX Dboard: B
>     RX Subdev: Unknown (0xffff) - 0
>   TX Channel: 0
>     TX DSP: 0
>     TX Dboard: A
>     TX Subdev: UBX TX
>   TX Channel: 1
>     TX DSP: 0
>     TX Dboard: B
>     TX Subdev: Unknown (0xffff) - 0
>
> Setting device timestamp to 0...
> Testing transmit rate 100.000000 Msps on 1 channels
> UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU ....... Lots of
> underflows
>
> Thanks in advance.
>
> _______________________________________________
> USRP-users mailing list
> USRP-users at lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
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