so i do need a new card not sure if those will fit my case here is my spec and if i ever go sli will i need a new psu?
and witch card is better to sli or recommend me a gpu budget 150-250$.
and i just really want a card that the fan will not be so loud like the amd 6850.
and i want the fan to last 2 years+
You dont need to apologize for bad enlish....its 4 languages in one having a fight. I have a 6950 2 gb. The best option is the 7850 due to higher OC potential and lower power draw. They are AMD cards so its crossfire not sli. The 7850 is powerful. You might not need to have a 2nd card at all. If you want to save money get a 2nd 6850 if you can find one. 650w is just fine. 2x6850 is amazing.
That depends entirely on your PSU's 12v rail, but I bet it can handle xfire'd 7850's easily. They only draw ~100w under load, so unless your PSU is designed with a 3 or 4 way split 12v rail (dumb design) you'll most likely be fine.