Hey! 
Yesterday i bought a new GPU (Gigabyte GTX 660 Windforce 2GB OC) and plugged it in my computer, everything was running fine and i played Splinter Cell Blacklist on ultra with no problems. But today its freezing sometimes, but only for like a half second. The wierd thing is that my computer makes a sound aswell, not any annoying or high sound but just a little sound (Sounds like hardrive but idk) and i don't know what to do. My psu is from my old prebuilt computer and its 500W (Acer Predator G3610)

Yesterday i bought a new GPU (Gigabyte GTX 660 Windforce 2GB OC) and plugged it in my computer, everything was running fine and i played Splinter Cell Blacklist on ultra with no problems. But today its freezing sometimes, but only for like a half second. The wierd thing is that my computer makes a sound aswell, not any annoying or high sound but just a little sound (Sounds like hardrive but idk) and i don't know what to do. My psu is from my old prebuilt computer and its 500W (Acer Predator G3610)