Best graphics card for i5 7400

[tsretv]

Sir, What is the best graphics card for the i5 7400, ga b250m, 8gb ram for 4k smooth video editing. Should I add another 8gb ram to it? I have a 2gb gddr5 gt 710 graphics card with me. Will it help me if I add it to the above said i5 7400 b250m mobo?

 

[kookie3010]

whats your psu?a 1050ti or 1060 will work great with the i5 of yours.

 

[tsretv]

whats your psu?a 1050ti or 1060 will work great with the i5 of yours.

 

[tsretv]

MY PSU IS CORSAIR VS550