My PC specs are: Intel Core i3 540 3.06 ghz Ram:2Gb Kingston Hdd:500Gb Seagate Barracuda HP DvD Drive 1260 Ati Radeon HD 6850 Monitor:Viewsonic 1938 19"inch
Stock Power supplier is at 450w so do I need to upgrade it?
More aboutwhich power supply choose
What's the brand of the power supply? 450W is theorectically enough to power that system. However, some power supplies, despite having enough power, are build from quality parts and simply aren't efficient enough.
It's all depend your budget, minimum 500W. Many good psu brand : seasonic, corsair, xfx, anteq, bequite, etc
500W or greater power supply is recommended for that graphic card so I`ll choose Corsair CX600v2 and that will be more than enough...