290's in crossfire, giving me hell

I bought a sapphire radeon 290 (reference design) to replace my geforce 760, seemed to run pretty well. I saw an ebay listing for an identical card and thought I should grab it since an identical card would be best for crossfire. It's turned out to be the most trouble I've ever had with a piece of hardware since the non-plug n play days. Here are just some of the things that have gone wrong:

Blue screens specifying an ati dll/.sys file failing
Micro-stuttering on most games
Screen-tearing with vsync on with most games
Lighting/shadows flickering on gta v and far cry 4
Trying to change graphics options crashes gta v
Random blank screen, ctrl+alt+del either does nothing, or I get a logonui.exe failure
Numerous times I've had to do a hard reset because I couldn't alt-tab to get control back
Displayport to hdmi adapter randomly blanks out/reports display as non-pnp display which kills eyefinity because that makes it think it's a 640x480 display

Cards are flashed with identical bios revision. My specs are:

Asrock z97 extreme4 (mentions sli and crossfire in the manual so it must support it
Antec hcgm 850w bronze power supply
i5 4690k @4.4ghz (going back to default clock speed doesn't change anything)

The temps on the cards seem to be fine, I have the fan set to kick in to make them run no higher that 70c.

Tried DDU to properly install drivers, install one card, then reset and install other card, etc
The only thing I can think of is that the motherboard drops the pci express speed down to 8x when running in crossfire, maybe this is causing problems... or perhaps my power supply? But it's crossfire certified, and a single radeon 290 only requires a 500w supply (though for some reason sapphire reference cards claim 700w, that doesn't make sense though)

This is probably the most trouble I've ever had with a single piece of hardware. I'm thinking of selling them at a loss and just getting a single geforce 980.

Did you try the new GPU by itself?

On that PSU you have two 40A rails. It does say on the PSU which rail is fed from which lead plug ins. Make sure that the cards are running on separate rails. Here's a pic

Johan45 said:

On that PSU you have two 40A rails. It does say on the PSU which rail is fed from which lead plug ins. Make sure that the cards are running on separate rails. Here's a pic

View attachment 164643

Click to expand...

That's how I had it in the first place, I actually changed over to using the same rails just in case that was the issue.

ATMINSIDE said:

Did you try the new GPU by itself?

Click to expand...

Yes, it runs fine.

As unfortunate as it may sound I've seen issues like this with replacements and adds switching platforms especially. If you have a spare hdd may be worth trying a fresh windows install just to test and make sure it works.

There are known bugs with the drivers that describe what you're experiencing. I too was going through that with my 7970 x-fire setup that drove me to the green team. X-fire is a mess right now.

Couple thing's to note.
Do not let OC tools auto start while installing AMD driver's it will break on reboot.
Do not install AMD drivers if your crossfire is on, Turn it off before removing old driver to prevent profile from following over to new driver.
I've had issues doing this where on reboot the pc will either lock or something similar.

Reinstall drivers with Crossfire disabled .. no issues.

Install both cards at the same time. no need to install the drivers twice its a driver suite both cards should be in place on driver install.

I would start new if i was you , I'd run driver sweeper completely in safe mode.
Then install the new driver after that from scratch with both video-cards in place and working.

Like i said make sure crossfire is turned off before you uninstall the current driver, And just to be safe after driver is installed reboot once before enabling Crossfire.

Also often i have had issues with their beta drivers so be aware it may be that.

Once everything is working i have yet to have a issue , all my problems I've had in the past with xfire on my 290x's are during the first couple reboots after driver installation.

PS: once driver is working correctly in CCC their is option to eliminate micro-stutter while crossfire is turned on. Its in the graphics options for games.

Might try changing PCI bus in bios to a set 8x if it isn't already, default is auto I think, it changes both cards when crossfire is enabled, and crossfire only works in full screen, so the mobo might be switching both pci slots and that is causing issues. Just a thought.