Quote Originally Posted by mac_69 View Post
You don't have to do anything in the bios, so if you think you have , just reset it to default values.
I'm running vistax64 and catalyst 8,8 and also had ran 8.7
Maybe your bridges are broken, but seems unlikely both to be broken. If single cards work in each slot then would say motherboard is okay. Recheck manual for which slots, but think you've done that

Here's some good links to ask 4850 cf users something specific, as far as I know they are all based on ATI spec design to be able to be CF'd
You can't mix 3 series and 4 series or 4850 to 4870, has to be apples to apples - your sure both are same?

http://ati.amd.com/support/driver.html

http://www.tweakguides.com/ATICAT_1.html

http://forums.guru3d.com/forumdisplay.php?f=19

http://www.hardforum.com/forumdisplay.php?f=87
Yes I'm sure even the brand are the same...BIOS version are the same...everything. However I don't have any confidence on this crappy brand of 4850 at all to be honest (Called Colamax and I'm sure you guys seldom heard of it)
Simply when I first bought these 2 cards, one of them have wierd display when rendering 3D Graphics and another one even don't have any screen projected to the monitor. I got it RMAed and they're checked that both are working right now. The question is, will a CFX cable associated with 2600XT being capable to use at 4850 crossfire??
Thanks for all your help anyways...