I buy two of these card . these video card a bit shorter than my previous card -lrb- 4870x2 -rrb- which would not allow I to run Battlfield 3 on 1900x1080 with ultra setting on my 27 '' Samsung lead monitor . I have to run it at 1600x1000 on medium setting . use one 6950 card , I be able to run bf3 at 1900x1080 on ULTRA setting . everything run smooth ! this card have a bio switch next to the SLI port . it be at default , but switch it towards the other end of the card and it will automatically turn on the 6970 shader of 1536 when you plug it in and turn on you comp . you will need about a 850 watt power supply if you plan on run two video card in Crossfire . you can not use three of these in crossfire -lrb- wtf I just find that out -rrb- . if you could run three , you would need a 1000 Watt power supply . warning !!!! dont rush into flash the 6970 model 's bio rom like I do . find the exact instruction for this brand and model . there be many 6970 rom flash instruction out there . Google how to unlock you hd 6950 ` dirt 3 edition ' and use the link from forum dot guru3d dot com -lrb- Amazon wont allow link -rrb- . these instruction be for this card . be a fool I flash another brand\/make 6970 bio rom and my comp 's monitor would not turn on during boot up , not to mention the usb mouse and keyboard not light up . if you experience this , then flip the switch back to the factory setting and you computer will recognize it . to bring you video card back to factory setting when turn the bio switch on , turn on you computer with the switch at the factory setting -lrb- bio switch off -rrb- . then while the computer be on , turn the switch on . then flash the correct bio rom for the 6950 2gb dirt edition . you comp will then boot up with the bio switch on and with the 6970 shader setting . I be also currently run a old i7 920 2.66 ghz quadcore overclock to 3.36 ghz and use 16gb of Ram at 1600mhz .