When running Forge 1.8, when I close Minecraft, the Java process (from task manager) does not close automatically, thus requiring me to close it manually every time, lest I get 40-60% of my CPU taken up by a program that should no longer be running. It appears that this effect can stack. I have tried installing different versions of Forge, and also tried updating Java. None of it works, but using a different minecraft version (1.7.10) does.
Log: None, minecraft is not crashing.