Hello, I am using a USRP B200mini with a sampling rate of 40MS that works perfectly fine connected to a laptop with USB 3. However, when I connect it to a Raspberry Pi 4 (which has two USB 3 ports) and I run the example benchmark_rate with the same sampling rate I get the output that I copy below. It seems that even if it is also operating over USB 3, this connection cannot meet the expected performance anymore. If I reduce the sampling rate (down to 12 MS approx) everything works fine. Any ideas about what might be causing this problem?
By the way, I already followed all the instructions explained at https://kb.ettus.com/USRP_Host_Performance_Tuning_Tips_and_Tricks#:~:text=Thread%20Priority%20Scheduling,-When%20UHD%20spawns&text=To%20address%20this%20issue%2C%20non,%2Fetc%2Fsecurity%2Flimits . ./benchmark_rate --rx_rate 40e6 --tx_rate 40e6 [INFO] [UHD] linux; GNU C++ version 8.3.0; Boost_106700; UHD_3.15.0.HEAD-0-gaea0e2de [INFO] [B200] Loading firmware image: /usr/local/share/uhd/images/usrp_b200_fw.hex... [00:00:00.000044] Creating the usrp device with: ... [INFO] [B200] Detected Device: B200mini [INFO] [B200] Loading FPGA image: /usr/local/share/uhd/images/usrp_b200mini_fpga.bin... [INFO] [B200] Operating over USB 3. [INFO] [B200] Initialize CODEC control... [INFO] [B200] Initialize Radio control... [INFO] [B200] Performing register loopback test... [INFO] [B200] Register loopback test passed [INFO] [B200] Setting master clock rate selection to 'automatic'. [INFO] [B200] Asking for clock rate 16.000000 MHz... [INFO] [B200] Actually got clock rate 16.000000 MHz. Using Device: Single USRP: Device: B-Series Device Mboard 0: B200mini RX Channel: 0 RX DSP: 0 RX Dboard: A RX Subdev: FE-RX1 TX Channel: 0 TX DSP: 0 TX Dboard: A TX Subdev: FE-TX1 [00:00:11.448560] Setting device timestamp to 0... [INFO] [B200] Asking for clock rate 40.000000 MHz... [INFO] [B200] Actually got clock rate 40.000000 MHz. [WARNING] [MULTI_USRP] The total sum of rates (40.000000 MSps on 1 channels) exceeds the maximum capacity of the connection (overflows (O) MSps). This can cause 22.7428. [00:00:11.766752] Testing receive rate 40.000000 Msps on 1 channels [WARNING] [MULTI_USRP] The total sum of rates (40.000000 MSps on 1 channels) exceeds the maximum capacity of the connection (underruns (U) MSps). This can cause 22.7428. [00:00:11.790580] Testing transmit rate 40.000000 Msps on 1 channels [00:00:11.891995] Tx timeouts: 1 UUUUUUUUUUUUUUUO[00:00:12.078147] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUUUUO[00:00:12.092404] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUO[00:00:12.108355] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUUUUUUUUU[OU00:00:12.123737] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUUUUOU[00:00:12.132437] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUUUUUUOU[00:00:12.142422] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUO[00:00:12.155257] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUO[00:00:12.168528] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUU[O00:00:12.178400] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUU[00:00:12.193251] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) OUUUUUUUUUUUUUUUUUO[00:00:12.204356] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUO[00:00:12.224770] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUO[00:00:12.235145] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUU[O00:00:12.247517] Timestamp after overrun recovery ahead of error timestamp! Unable to calculate number of dropped samples.(Delta: -3170 ticks) UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU[00:00:12.475571] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:12.575910] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:12.676171] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:12.776414] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:12.876663] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:12.976968] Receiver error: ERROR_CODE_TIMEOUT, continuing... [00:00:13.077257] Receiver error: ERROR_CODE_TIMEOUT, continuing... terminate called after throwing an instance of 'uhd::io_error' what(): EnvironmentError: IOError: usb tx2 transfer status: LIBUSB_TRANSFER_NO_DEVICE[ 00:00:13.083166] Caught an IO exception. EnvironmentError: IOError: usb rx6 transfer status: LIBUSB_TRANSFER_NO_DEVICE
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