x2 4850s in crossfire...help pls?

Well i do know that sometimes there is an option for enabling/disabling crossfire in the bios. Apart from that, are both cards getting power, all leads attached etc.
Also i know this is daft but you do havethe cards in the correct slots ? (Yes i know but i had to ask) the blue ones right

Mactronix

Update the VGA driver and see what happens

The dvi for my monitor is plugged into the 4850 in the PCI 1 slot . The Device manager shows the 4850 in PCI 1 slot enabled, and the 4850 in PCI 2 slot enabled. on CCC (catalyst control center) in the graphics hardware tab its showing the PCI 1 slot enabled as the Primary Adapter. The 4850 in PCI 2 slot is showing in CCC as disabled...

I took out one graphics card at a time to double check that both cards were working and both slots were working...

I'm stumped on this one guys...

k thanks, ill try

Personally by now I would have just formatted the stupid thing ^_^. Anyway check your BIOS to see if you have any settings for crossfire. As mrbobc said, it's probably just some rouge file or registry setting mucking everything up.

The only way to get this to work is to roll back to catalyst 8.10 (about 6 months old) , i know this because i had the EXACT same problem with my two 4850's. and the performance with 8.10 is terrible too. i get the exact amout of fps in warhammer with the single 8800 gtx i borrowed from a friend. this month's drivers (9.4) were the last straw, they did nothing to fix the issue. i have sold off my two 4850's and picked up a gtx 280. . if you browse the ati forums you'll see that you are not alone with this and it is pretty common. just to clear the air too, i am not a fan boy, i go where the price/performance is... but after having this issue for the past SIX MONTHS i am done with ati.

hey, thanks guys...this has been driving me insane for quite some time....ccc 8.10 you say?

and yes, i did use the DRiver Cleaner in safe mode...

I have this same problem with 2xHD4850's, and the only drivers that give crossfire is 8.10. I heard this is a bios issue, because some companies thought it would be cool to put old bios on the cards. So if anyone has a fix please help. I really don't want to flash bios though...

and in addition to having both a amd and an intel chipset to test it on, i also had three diff crossfire bridges, two diff pwr supplies (corsair hx620 and a ocz gamestream 700w). so believe me when i say that the ONLY fix i found was to roll back to 8.10 and below.

see, i have the MSI x48 Platinum MoBo...and ive been reading the manual with it...it says that the MoBo is already crossfire ready and nothing needs to be changed in the BIOS for it...it states that its all involved with the Driver and software like CCC for example...

did u try uninstalling the cards in device manager? it has worked for me when all else has failed!

if you have then a fresh install of windows is the only way you'll know if its a driver issue or a hardware issue.

Gahhhh, alright, 2 weeks later after i made a whoopsie...in the process of flashing my BIOS, one of my sticks of RAM decided to die on me...

I now have an updated bios, a fresh install of vista, latest driver for my radeon 4850, bridges connected properly and identified in my device manager, crossfire is already enabled in bios...

what the freaking hell could be the problem now?????

cowy... It looks as though you've tried everything suggested, other than calling the card manufacturer and telling them the dang things aren't working correctly. Maybe it's time to do that.

Have them troubleshoot it, as they have the most experience with their own particular hardware. Bring up the point expressed here about the card BIOS, and have them RMA'd if they can't get 'em to work. You can also try contacting MSI since they're installed on their mobo. Perhaps they have a beta BIOS or some trick that isn't covered in the manual to get it to work correctly.

This happened with my 4850s in crossfire. I plugged in both cards without the crossfire connection, booted up, device manager read them both. then i shut down, plugged the crossfire connection on the top of both cards, booted up and still CCC didnt give the crossfire option. I didnt change any connections after but I did one more reboot and it gave me the option after that. Only difference here is I'm on xp32~