If you are running SABnzbd then you should already know that when it goes to unrar a file or par2 fix/verify them it can be so intensive that if your watching a movie using Plex it can actually cause you to buffer and wait for things to catch up. I'm gonna explain how you can fine tune SABnzbd to fix this issue. Requirements: nice ionice par2 Linux / OS X If you are running Windows you may only use the par2 extra parameters. As nice and ionice is not available. If you are on OS X you may follow the nice and par2 parts of this guide. If you are running Linux you may follow this guide completely. If your running Linux you must acquire the multi-core version of par2 from above. The Windows version of SABnzbd will come with the multi-core version of par2. Let's get started then... Now open up your SABnzbd Web UI. From here go to config > General. Here is a article cache limit. This option will reduce hard drive access by caching it in ram. As you can see from the picture below I have -1. Which means unlimited. On average it uses just over 200mbs on my setup. You can adjust this as you wish using for instance 1G, 200M. 0 will disable this option. Go to Config > Switches. Here you will see Extra Par2 Parameters, Nice Parameters, IONice Parameters. As you can see I've entered "-t0" for Extra Par2 Parameters. This means that it will use multi-core for repairing, however it will not for verifying. Which will prevent disk thrashing. You may also use "-t-" which forces single core. Also "-t+" which forces multi-core. My nice says "-n10". You may need to adjust this to your setup. My ionice says "-c2 -n4" You may need to adjust this to your setup. I'd recommended just using my settings as they do work well and are the popular settings based on the SABnzbd Wiki. Do this and you should end up with a powerful SABnzbd but yet it won't kill your media server when it decides to do an intensive operation.