Will my video card work for Oblivion ?

I got Oblivion (elder scrolls) but it is really to the point of unplayable it is so slow . I currently have a FX 5200 nvidea and a kinda old computer . I have completely cleaned my computer of all other little programs , and all that jazz . Now I have found a craigslist ad for a AGP ATI 128mb 9700 pro , and I was wondering if anyone has the same one and could play oblivion before I buy it .