Forum Post: RE: Overflow/underflow issue in ZCU102+ad9361(FMCOMMS5) through GNU Script. I have installed Kuiper Linux on the SD card. The GNU Radio flowgraph is running directly on the ZCU board . The flowgraph is a simple loopback: FMCOMMS2/3/4 Source → Throttle → FMCOMMS2/3/4 Sink The IIO context is connected via the LAN port . My goal is to transmit exactly what I receive , essentially a real-time loopback. However, I’m encountering underflow/overflow issues when running this script at higher sample rates (e.g., 30 MSPS and more). My Questions: Why are these underflow/overflow issues occurring in GNU Radio? I'm running script in ZCU itself. How can I avoid these issues at higher sample rates? Are there buffer or threading optimizations I should consider in GNU Radio? Would using iio_readdev | iio_writedev provide a smoother loopback? Is this the recommended approach for high-throughput loopback testing? Thank you..
https://ez.analog.com/fpga/f/q....-a/597232/overflow-u