Originally Posted by theducks
In Calibre; Preferences; Behavior; Set Job priority to LOW, that will let other processes function a bit.
If I may take this up ...
I would actually expect to have more than "a bit" if the prio is set to low. But calibre-parallel uses 50% of CPU anyway (XP, double core). More precisely I would expect, that on low I could use my computer pretty much normally. So maybe we should then have a "very low" setting? Personally, I would not mind if a conversion (typically epub>mobi for me) took 10 minutes. But to hardly be able to even surf this forum while it converts is simply not helpful.