Weird Problem: PSU & Crossfire

I am trying to setup Crossfire on my current system. The way you do so is to install the card w/ crossfire connector and enable crossfire in the Catalyst control center. So I hook up the power connections & cross fire connector to my 2 6970s and power up the PC. I boot into windows and then into Catalyst. However, the option to enable crossfire isn't showing up in Catalyst at all.


I've uninstalled and reinstalled catalyst all to no avail. So my next thought is...it's the PSU or the PCIe slots. I boot each card individually in both PCIe slots on my mobo just fine. Even game with both cards in both slots (one at a time). So that rules out disfunctional PCIe slots.


Now I go on to test the PSU. The PSU is fully modular with 4 PCIe cables (2 6 pins and 2 8 pins). I boot each card individually, in each PCIe slot using the 6 & 8 pin PCIe cables I've been using for the past month when I only had one 6970. The second I go to boot with one 6970 using the 6 & 8 pin PCIe cables that I haven't used yet (while the remaining 6 & 8 pin PCIe cables are still plugged into the PSU) the system boots but wont post and no video is displayed on my monitor.


Thinking maybe it was the load I was putting on the PSU...I used a molex to PCIe 6 pin adapter. So now I try to boot with only 1 6970 hooked up to the PSU via 8 pin PCIe & molex to 6 pin PCIe adapter (still with the other 6 & 8 pin PCIe cable plugged in) the same thing happens...PC boots up but it doesn't post and there's no video. But, the PC will boot and post with one 6970 powered via the 6 & 8 pin PCIe cables I've been using for forever (even with the other 6 & 8 pin PCIe cables plugged into the PSU but not into a video card).


I'm receiving a more powerful PSU tomorrow. But do you guys agree with my assessment that my PSU can't handle the load or that the 2 modular PCIe cable connections that I only started using today maybe disfunctional?


[U]Specs of my PSU[/U]:

[IMG]http://i56.tinypic.com/308cv87.jpg[/IMG]


Forgot to add that GPU-Z and device manager aren't showing 2 6970s installed.

sounds like you might want to up your power supply, it also could be a motherboard problem to.

skullabyss said:

sounds like you might want to up your power supply, it also could be a motherboard problem to.

What leads you to believe it's a mobo problem? I've gotten both cards to work individually in each PCIe slot on the motherboard just fine.

kk, so it might be your PSU or even the drivers aren't working right then

im not sure if you ruled this out yet but it might just be a faulty cable or modular plug

the only other thing i can think of is that the 12+ rail could be dieing

if you have a spare psu laying around, maybe power one of the cards solely with that?

ok finished reading more into it, test your new psu tomorrow, if the problem still exists more than likely its your motherboard kicking up a fuss. are the gpus reference? also a bit confused, you say that the option to check the crossfire box in catalyst isnt available, is that with both cards hooked up (and crossfire linked) with video giving output? maybe a reinstall of windows on a separate hdd as a test maybe useful >software problem?

just to be sure you did install the Crossfire drivers right?

Beehoo said:

just to be sure you did install the Crossfire drivers right?

Umm...I think. The crossfire drivers are just included in the Catalyst 11.4 suite right?

AKIMbO said:

Umm...I think. The crossfire drivers are just included in the Catalyst 11.4 suite right?

yes they are.... have you tried loading up both cards without the bridge on, and have both powered???

ztrain said:

yes they are.... have you tried loading up both cards without the bridge on, and have both powered???

Yeah, I tried that as well. The fans on both cards were spinning but only one of the cards (the card with the 6 & 8 pin PCIe cable that I've used for forever) was recognized. Didn't matter if I switched the cards into different PCIe slots...same outcome.

wait wasn't one of those cards the one you got used? maybe that's why he sold it?

GigaBuster.exe said:

wait wasn't one of those cards the one you got used? maybe that's why he sold it?

Yes, one of the cards is used. But it is working. I verified it works by using it by itself, w/o the other card, and gamed on it for an hour without problems.


I'm really puzzled. Hopefully the new PSU tomorrow solves this problem. If not I'm going to reformat like Gandu told me to. If both of those don't work, then it must be the mobo and I'll have to replace that.

TRy reseting your bios

Beehoo said:

TRy reseting your bios

Already cleared CMOS. Loaded optimized defaults. Booted completely stock on everything. No dice. :(

could you link the motherboard you are using?

GigaBuster.exe said:

could you link the motherboard you are using?


Foxconn Bloodrage http://www.newegg.com/Product/Product.aspx?Item=N82E16813186163


It's the non-GTI version. I also flashed the BIOS to G42 which is the second latest beta bios (didn't do anything except add Fermi support).

Have you tried completely removing the drivers with something like driver sweeper, and then reinstalling? It did the trick for me once.

Also, my crossfired cards can act a bit funny if I put the DVI cable into the bottom card (I get no signal). Try putting the DVI cable into all the outputs to see if it makes any difference.

Boov said:

Have you tried completely removing the drivers with something like driver sweeper, and then reinstalling? It did the trick for me once.

Also, my crossfired cards can act a bit funny if I put the DVI cable into the bottom card (I get no signal). Try putting the DVI cable into all the outputs to see if it makes any difference.

Tried all that. Uninstalled using driver sweeper and then reinstalled several times. Tried all the DVI ports too.

Just switched out the PSU for an AX1200 and crossfire is working. I noticed on my old PSU the 6 & 8 pin PCIe modular hookups were a little loose...so the connection to the PSU itself must have been messed up. Thanks for all the help everyone!