Hello Józef!
I just updated to the Version 1.40 Beta-svn655. I'm really amazed about how fast the new asynchronous copymode is. Got 140 MB/s on a not so new Backup HDD, where the old Version only got about 50 MB/s. Nice!
But with the new speed, there are new problems never to be thought of

: My basic problem is, that i can't watch a movie (or play a game, etc.) and have CH copy some files in the Background from the same drive, because it leeches literally every drop of performance the drive has to offer. Is there a way to decrease or limit the max. I/O CopyHandler can use? The best way of course would be something like processor priorities but on drive level i.e. CH can use the maximum IO, but when some other program needs to read or write, CH will step back.