Woah, woah man you cant run a 660 or a 660 ti or a 7870 especially the 7870. They all require a 450 watt or greater and the 7870 requires a 500 watt or greater. I would go with the radeon hd 6670 or a 7750, maybe, you mifht could run a geforce gtx 650 but then again i wouldnt risk it. So yeah i would go with a 6670 or a 7750 for better performance. You cant run much with a 350 watt psu. Sorry man a psu is a good investment.