I have a intel i7 920 2.67mhz with Asia p6t deluxe mb and 12 gig ram corsair 2000mhz ati 4870x2 card and raptor 600 gb hard drive. I wanted to upgrade the video and now some people say do my and CPU as well. I have 1000 power supply as well corsair gold. I don't want to spend a lot of money now.need opinion