It's DDR3, an entry level GPU. You can do far better for the money. Try this list and post again. DO NOT BUY THIS CARD.
-> http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107.html
As to the PC specs I missed the PSU detailed ratings. Tell me the amperes on the +12V rail.
Bob
Computer Model and specs: Cyberpower PC Gamer Ultra 2098 (GU209
AMD FX-Series FX-4300 (3.80GHz) 8GB DDR3 500GB HDD Windows 8.1 64-Bit
Specs are here: http://www.newegg.com/Product/Product.aspx?Item=N82E16883229285&cm_re=gaming_pc-_-83-229-285-_-Product
Video card: http://www.newegg.com/Product/Product.aspx?Item=9SIA30R2NH6445&cm_re=video_card-_-9SIA30R2NH6445-_-Product
Also, will this card run games like the Witcher 3 and Arma 3 very well? Would you suggest another for about the same price? Thank you for the help!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic