High ConEmu I/O rate and CPU consumption

Some process monitoring tools (Process Hacker or Anvir for example) may show high I/O rate of ConEmuC[64].exe and ConEmu[64].exe processes. Windows 8 Task Manager do not do that by the way.

The reason is simple - ConEmu utilizes Named Pipes for interprocess communication with RealConsole and graphic part (GUI). Named Pipes are not related to disk activities at all and I believe these tools just confuse users summarizing both real disk activites and ‘in-memory’ transfers.

Well, most of I/O transfer actually consists of two parts (types):

  • Continuous scanning of the RealConsole surface
  • and transmitting real changes to the GUI.

We can’t decrease throughput of first part without decreasing the responsiveness of ConEmu but there are two options on the Features settings page allowing to dramatically descrease I/O rate of the inactive consoles (Tabs or Panes) notably ‘Sleep in background’ and ‘Retard inactive panes’.

The thoughput of the second I/O part can’t be controlled directly by user, but it has linear relationship with the number of changes occurred in the RealConsole. However, ConEmu tries to limit its ‘speed’ to something about 60 FPS. And if there were no changes in the console, there would be no I/O transfer of this type.