4890 + 4870 Crossfire not working :S

What OS are you using?

Here is a chart that may prove useful. Seems the 2 GPUs you have are not compatible together for CF (connect with bridge), but can support CrossfireX (no bridge).

http://game.amd.com/us-en/content/images/CrossFirex/CF_...

dude those are 2 diffrent cards..... Ofc you cant crossfire them. Return the HD 4870 and buy another HD 4890 if you want to do crossfire

so apparently i tried everything except reading about the difference between crossfire and crossfirex, i just assumed that you would always need the bridge -_-
ill try the two cards without the bridge and let you know, cheers guys!

You should need the bridge. You can only run one monitor however. Unplug the monitor attached to the secondary card and see what happens.

I tried both having no bridge and no screen with the bridge and then having no bridge AND no screen attached to the second card (with a fresh driver install before each) and nothing. is there an option i need to turn on in the bios? i have searched in the bios and the motherboard manual and i cant find anything that directly relates to crossfirex. oh and i am running XP, edited top post.

I am not sure if it will help but the 4870 is this one GDDR5 1GB Gv-r487d5-1gd
I cant find the exact model of the 4890 but it is a 1GB GDDR5 powercolour card with the reference cooler. im starting to think that catalyst is thinking they are too different to be crossfired -_-

Which GPU is the "primary" GPU? I suggest the 4870 as the primary and the 4890 as the secondary. Nothing to lose, but keep in mind "IF" it works you don't get 2 4890 level GPUs, you get the least common denominator in terms of performance (2 4870s).

okay, so i borrowed a 4970 from a friend SO I AM NOW RUNNING TWO 4870S reinstalling drivers now!

okay, its no different with two 4870s. tried with no bridge, one and two bridges. tried plugging just one monitor into each card. im stumpped.[edit] Gpu-z is showing the second card as x4 bus interface. the motherboard clearly states that it is capable of x8 + x8.

[edit2] okay now that the 4890 is back in they are both saying x8 bus interface, still not working =[

the 4870 in the lower slot: Bus Interface PCI-E x16 @ x8

the 4890 in the upper slot: Bus Interface PCI-E 2.0 x16@ x8

does that "PCI-E 2.0" have any bearing on the situation, or rather, does the other card NOT using it have any bearing on the situation? thx

To be clear, when you had 2 4870s, it didn't work. Assuming you are using 10.7, did you reinstall 10.7 after you plugged the second card into the system (with bridges attached)? Even though it should work, don't assume CCC will initialize properly after changing the physical config of the system.

When you have a single card installed, does GPU-Z show x16 or x8?

I, like nforce4max, am starting to wonder if your mobo has a problem. Still, we aren't quite there yet. Even at the lower bandwidth rates, when you had 2 4870s installed, they should work in CF as long as the drivers are installed properly.

I have the same mobo and im curious, where did you find a crossfire bridge that could gap the 2 ports in between the 2 PCIE ports?

@ COLGeek when i had the single card, i had x16, with both it went down to either x8 and x4 or x8 and x8 it would change between the two randomly each time i rebooted. I was indeed starting to wonder if it was a motherboard issue but i was considering upgrading to windows 7 anyway and what nforce said made me think that XP was in some way not compatible with two non identical cards in xfire. so as a last ditch effort before sending in the motherboard for RMA i thought id go out and buy windows 7.

Within about 5 minutes of a full reformat and fresh windows 7 install everything was working! just installed 10.7 with both cards in and BAM. to be VERY sure it was XP causing the issue i did a fresh reinstall of XP and followed the same steps installing the drivers as i had done with 7 but that did not work.

so yeah, anybody else having this trouble with xp, install windows 7. although for me it was a little bittersweet as my PSU was NOT getting along with two 48xx series graphics cards and was getting VERY hot so i decided to take one card out and wait until i had they money for a HX750 PSU.

thanks to all for the help

also @ CG_GAMER

I just used the standard Xfire bridges that came with the 4890 and the 4870, maybe you have an older bridge? the ones i have arent the solid ones they are the ribbon cable ones. sorry i cant be of more halp.

[edited for grammar]

Best answer selected by keto82.

This topic has been closed by Mousemonkey