Hello,
While working on a couple of projects, I encountered an issue where, when the CPU was under heavy load, the flowgraph would start having dropped samples occur in a non-deterministic fashion. This was strange as the flowgraph was reading in data from a file and so it should've adjusted the speed as needed to work with the resources available. After some tests, the Polyphase Clock Sync was found to be causing the issue. Basically, when under high cpu load, the presence of the block would lead to non-deterministic behavior and the occasional dropping of samples. I then replaced this block with an M&M timing tracking block and that has seemed to resolve the issue. This was in GNU Radio version 3.7.14.0. I'm not sure if this issue has been pointed out or addressed before but I wasn't able to find anything online about it.
