Xfx 780i SLI problems

I have the same board and I can tell you that it is not the board. You can't normally sli a 9800gt with a 9800gtx. You will have to mod the bios on the 9800gt and rename it with the same device id as the 9800gtx in order to get sli however it will not be as good as a true 9800gtx and in sli you will still not have the same performance as if it were to be two 9800gtx in sli.

ah thanks for the info   but i'm not going to buy a new card just yet. so is it hard to mob the 9800gt bios ?

Mod *

You can but you must use the stock bios and then edit the name and device id so that the driver recognizes it as a 9800gtx while the clocks, volts, timings, and every thing else remains as before. It will not perform as good as a 9800gtx but it will sli with one however scaling will not be as good compared to having two 9800gtx in sli. Both cards have the same gpu core however one is what we who play wow like to call a nerf as in not has good or more common used words here are disabled units.

But i guess it's better than one gtx ?   do you have any name of a program i can change this with ? i found a program called RaBit, just wonder if this is the right one ?

do you have abit more info how i do this ?

No it isn't and I suggest that you just leave it alone and get either another 9800gtx and use the 9800gt as a physx card or get something much more powerful than either solution like a GTX 460/470. Telling by how you seam to be new with these things I suggest that you avoid it or at least get some practice with a junk card before flashing any thing that is of value.

nbitor and nvflash

You will need to research online for commands as well flashing a multy gpu system. I have your board and the pci-e switch will come up in nvflash and if you don't know the proper ID of the chip that you are trying to flash it will fail every time with the bios rom being rejected.

thanks for the help ^^

Your welcome and Good luck, even if you don't get around to it or it doesn't pan out i hope that I taught something that may be of help down the road.