upgrade video card

I have a cyberpower desktop. Win 7, 64 bit, Intel Core i5 3450 @ 3.10GH, 8.00GB Dual-Channel DDR3 @ 665MHz RAM, DELL (1440x900@60Hz),
ATI AMD Radeon HD 6670 (ATI AIB) graphics.
I want to upgrade my video card to play high demand games, like FarCry 4, etc. I have attached specifics, not really sure what it all means, if someone can help me.

 

Far Cry 4 is not going to be easy for your system.
http://www.game-debate.com/games/index.php?g_id=8147&game=Far Cry 4

If you are willing to spend 400 - 500 USD you can probably play it pretty well.
Something around the ATI 290x or 970 GTX
http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html
I would not go more than one step below them and you may need to upgrade your CPU if you don't like the gameplay.

 

No need to spend 300 or more to get good performance.
Look at the AMD R9 270 cards for something in the 225 area that will fit your needs.

Just make sure you have a power cable available in your system for the new video card.

 

whoops. Prices have come down. You can get an R9 270X video card for about 120.

That would be a perfect fit for your system.

 

Abekl is right if you want mainstream gaming, for high end you will need more.

 

While testing out some hardware combo's recently, I played FC4 on a 3.3GHZ i3 Ivy (~65% usage), 8GB RAM and an HD7850 at close to Ultra across the board at 1920x1200. FPS might have been dropping close to 25 at times but no stuttering was apparent - more sensitive players may have noticed some, especially if they're used to playing it with FPS of 45+.

Some of the problems are that it won't install on a dual core HT. It's poorly optimised. Steam and UBI add their own layers of fail/complexity that might take weeks to iron out (sometimes takes 4-7 reinstalls of a game with Steam to get a 'good' install, verification is not foolproof).

On your rig/monitor with a 270, you should be able to play it comfortably at High or Very High settings - provided you have a good quality (XFX/Seasonic) 450+W power supply fitted.

The above i3 was an ITX rig with a Seasonic 360W Gold PSU, drawing ~140W from the wall; with your i5, Bronze PSU and a 270, expect ~250-270W at stock speeds.