Video editing and gaming system build

PSU isn't that good and X58 platform is outdated...If you want hardcore gaming 6870 isn't the right card...

oh, ill change that the gpu, so 20GB ram ddr3 1600 mhz will go with intel i7 950?

Hi, welcome  

I have some thoughts for you to consider:

1. I would strongly recommend that you go with the I-7 2600K CPU (Socket 1155) for your stated use. It is a much better choice - it is a lot faster than the I-7 950. I have owned both the 950 and I currently own the 2600K

2. Go with a Z68 motherboard like the AsRock Extreme 4 Gen 3 that is compatible with the new Ivy Bridge CPUs that are coming out and are PCI-E 3.0 compliant. The Intel video rendering of the Z68 motherboards integrated GPU is far faster than any other solution you may consider. The cost is about the same for these motherboards ( the Extreme 4 is around $180)

3. I would recommend the Noctua NH-D14 CPU cooler for your build. It is about $40 more than the Artec Freezer but it is a much better cooler

4. Because you are working with video I would suggest that you go with 16GB (two sets of 2 x 4GB RAM in a matched set) of 1600 of 1866 RAM. This is one situation where you will need the most RAM that you can get. Normally 8GB (one 2 x 4GB) is sufficient but in your case you need more

5. I would strongly recommend that you move up to the 2GB ATI 6950, GTX 560Ti or GTX 570 graphics card. Any of these are more powerful for video editing

6. You also may want to consider going with a $120 GB SSD. Look at the Kingston Hyper X, the Corsair Force 3 GT (emphasize the GT), the Mushkin Chronos Deluxe (emphasize the Deluxe), the OCZ Vertex 3 and the Patriot Wildfire. Buy the cheapest one if budget is an issue. If you want the fastest one, the Mushkin Chronos Deluxe is the fastest 120GB SSD on the market right now

6. I would strongly recommend the Corsair HX 850 PSU. It is on sale at Newegg right now for $143 and it is one of the best power supplies on the market. Your system will only use between 300W - 400W but this will put the HX 850 in its most efficient power range where it will be 91%-92% efficient. It will run silent and it will not heat up your case. I own the HX 850 and it is an amazing PSU. It also comes with a 7-year warranty. Don't mess around with cheap PSUs, they can ruin your system and make your life miserable

7. Your HDD choice is excellent (I own the F3)

Good luck with your build

Good luck with your build.