High speed async fills buffer quickly

Thanks for writing in about this, and sorry for the trouble! I wanted to add a few more things to Tim’s reply, for context.

  1. The buffer limit in the software only applies while running the capture. When adding analyzers to the capture after recording is complete, the buffer limit is ignored. (we’re not sure if this is a feature or a bug, but it needs to be addressed either way. We need to make big improvements for high-memory users)
  2. For digital signals, we run-length encode the data, meaning we only store information when the signal changes. How long you can record for is directly determined by the number of digital transitions per second. You can record 9600 baud serial for extremely long periods of time, but 2.5 Mbit/sec (especially at high utilization) will consume memory very quickly.
  3. We store protocol results very inefficiently at the moment, and this is in our backlog list of things that need improvement. In the meantime, what Tim mentioned - recording without the analyzers, then adding them after the capture, will help a lot. First, it reduces CPU usage during the capture, and it will ignore the memory limit. Second, once the capture is complete, the recorded data can be allowed to page to disk normally, so even if the memory usage is very high - perhaps higher than the installed RAM, the software will continue to work. We recommend using saved presets to easily switch between no analyzers and all of your analyzers properly configured. You can save all of your active settings, remove all analyzers, and then save another preset, and then alternate between the two.
  4. The saved files only contain the raw digital and/or analog data, they don’t contain analyzer results. That’s why the save file sizes are so different. When you load a saved capture, the analyzers are simply re-run.
  5. For huge captures, I recommend only having one open at a time, and I recommend saving them right after your capture is complete.