I noticed that when recording for a long time the hard disk can fall behind the current capture. When that happenes the hard disk utilization is 100% but it's not good it causes lag in game.
My solution for this is that when this is occurring Bandicam can use the RAM instead, I mean why not? If one has a plenty of RAM it will be no issue for him. And the errors in the hard disk can disappear.
So it will look like this: The hard disk is slow > Bandicam uses the RAM to remove laginess > The hard disk still write but with X% bitrate per second > Everybody happy.