I have just built a pc for the first time and am not familiar with optimal performance specifics. Norton gave me a usage warning that one or more cores reached near 100%. This occured as I loaded a heavily populated area of WoW with maxed settings. I am wondering if this is normal and/or safe for my pc. I am using an AMD Phenom II x6 with 8gigs of ram and a Radeon HD 6870. Core temp reads 26-28c during gameplay and 18-21c idle.