Crossfire Issue...Can't figure it out

[nbrikha89]

Asus 990FX
AMD Phenom II 840 @ 3.1GHz
16GB DDR3
XF HD 5770 (XFX and Saphire)
Cooler Master extreme Power 600W

I have an issue I just can't figure out. I crossfired a second HD5770 to my existing XFX 5770. Installation went fine. Nothing weird in putting it in and installing proper drivers. The bridge is on fine and with my mobo, they actually sit a little further apart from each other than normal, giving plenty of space for air to cool down. I did a stress test on my graphics. The XFX is the primary card and it holds on strong. But the Saphire, just a few seconds into the test, goes all 0's and the fan drops to 20%. I tried testing the Saphire by itself...and it does great. It's only in crossfire do I have this issue. Any one got any ideas? I don't want to just start throwing money into this again until I know what's wrong. Thanks

 

[OhSnapWord]

Is this your board?

Newegg.com - ASUS Sabertooth 990FX AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS

Verify that you have the cards in the x16 slots. Switch the cards so that the Sapphire is the primary card and see what happens.

 

[nbrikha89]

Switched to the sapphire and it didn't recognize the crossfire. the sapphire has two gold teeth and the xfx has only one. It happens to be that if the XFX is secondary, the second gold tooth on the sapphire is the one that connects to it. I figured that's why the crossfire wasnt being recognized

That is my board. I plugged them into the proper places. They are all x16 slots but the top black one is not to be used for video card. I have the two plugged into the two green slots.

Both cards work perfectly fine by themselves...it's crossfire I have an issue with. PSU? maybe?

 

[nbrikha89]

Okay, so now it's no longer going to all zero's. But it's not rendering anything. Every bench I run, it's just sitting at idle. The first card can be at max capacity, but the second one is doing nothing. Cinebench, 3dMark, all the same...no activity.

 

[OhSnapWord]

Might be. Sapphire might be defective, they did away with dedicated master cards years ago. The Sapphire should work as the primary card. Test a single card in each of the x16 slots. Although it's not likely, you might have a bad slot.

 

[nbrikha89]

Didn't think of that. Will do. Let you know. So I can just run a single card on that second green slot even though it's not what Asus recommends?

 

[OhSnapWord]

It should run, performance might not be optimal though.

 

[nbrikha89]

Both cards work in both slots.

 

[nbrikha89]

So now, I've reversed it. The Sapphire is at top, and the XFX is at the bottom. Crossfire is enabled and working at idle no matter what positioning the cards are. But same problem. The XFX, since its on the bottom this time where the monitor is not plugged in, went all 0s. But then it came back up after a minute or so. I'm gonna try and run a bench or two and see if I get anything.

 

[nbrikha89]

I'm no longer crashing. The cards seem to stay stable. But there's no sign that the crossfire is giving me any benefit. Any games or benches where I can specifically see the difference?