Can you explain more on this new feature? Does my CPU mine automatically when i open the wallet? I can see that my CPU is using 25% now the wallet is open, pretty cool. I didn't select how many threads though, how many threads is 25% CPU usage?
By default it uses 1 thread, so you probably have 4 cores on your machine.
This thread runs at a low priority, so it shouldn't affect other processes on your machine.
Under Settings (the drop down menu) you select how much CPU to use on mining. If you have 4 cores and select 4 threads, it will attempt to use all your CPU power.