it wont b fully compatible . but dx10.1 will have minor changes , so not many games will demand that in the next 1-2 yrs ..if u own a dx9 card now , no point in changing . if u're buying a new one neway , a dx10 maybe better . ofcorse , if u intend to change the card again within a year , 7900GS will b better than 8600GT .