Some quick specs: i5 2500K (not overclocked, yet.) Sapphire 7870 OC edition Asrock Z77 Extreme4 Corsair H40 Hydro cooler Fractal Arc Midi case I had a friend assist me with the build, but we didn't use any thermal paste on the CPU as we didn't have any AS5 available (something he claimed we needed). Just wondering how important this paste is, and what are safe operating temperatures for my core and GPU. It seems to idle around 25-30C, but when gaming will spike to 40-45C. Is this okay? My friend claimed anything over 45C was bad, but after some google research it seems a lot of computers run at 70-80C. Thanks for any help.