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PC Drivers & Software

terrh
Adept I

7990 crossfire not working [SOLVED]

Computer specs:

Ryzen 1700X
Gigabyte mobo w/ crossfire support
one AMD HD 7990 card, monitor plugged in to one of the miniDP ports on it, not the dvi port.  Proper dual 8 pin power, 750 watt PSU. 
Windows 10 fully updated
DXDIAG reports no problems
Radeon software version 19.4.1

Pretty fresh install of 10.  Brand new install of 7990, never previously used this card on any pc.

crossfire settings aren't showing up anywhere, and when I try to run either furmark or 3dmark only one GPU core gets warm to the touch, the other stays at idle. 

Trying to verify that this card fully works and is stable before my return window closes.  Any help would be appreciated!

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1 Solution
terrh
Adept I

OK, Got this working!

- newest drivers (19.4.1)
Just ONE 7990, the crossfire is internal.  Have not tried this with a pair of cards yet

I did several things at the same time and I am not sure if all were required to fix this, and I have also noticed that this is not 100% perfect - sometimes crossfire options don't exist in the "global graphics" page of Radeon settings, and when that is the case crossfire still doesn't work.  But a quick reboot solves it and this only has happened once after solving my main issue.

The things I did to make it work:

Removed and installed the card (doubt this did anything)
Disable CSM in the BIOS
Set windows 10 power settings to "high performance" instead of "balanced" - Suspected it might be turning the 2nd gpu off
Used Afterburner to disable ULPS Again (not sure this mattered either - but it sure might have been it)

This particular card is now working perfectly.    And is surprisingly fast for such an old card. 

View solution in original post

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9 Replies
terrh
Adept I

Found some people online that said that installing old drivers would help.  Removed all existing drivers with DDU and installed 15.7.

In CCU in it, the second GPU just shows up as "disabled" but it doesn't say why.  No crossfire settings visible anywhere. 

Device manager shows 2 GPU's, both enabled with no problems.

Installed afterburner and disabled ULPS, that didn't help either.

I figured this had a small chance of working, but tried anyways. 

Going to use DDU again and install the latest drivers again, but I'm sure that won't fix anything, but just to get back to a modern "state". 


Any ideas here?   I can't think of anything else to try. 

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Do you even see Crossfire option in AMD Settings when you install older drivers?

Might be a bad GPU, might be bad drivers, just do yourself a favor and buy something else.
There are some really good deals on new cards now.

Bye.

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Hi,

The drivers for HD7970 are not working properly for almost 1 year now.
There is a very long thread about it.
I may presume 7990 which is two 7970's on one board is suffering problems as well, although your 2nd GPU may be dead.
I would download and install Radeon Crimson ReLive 17.4.4 WHQL Driver and see what happens. It might not even install though depending on the Windows 10 version. 
I pick that driver because it is the last WHQL driver before RX Vega was launched which was a bad thing for driver quality and stability on older AMD GPU in my opinion and experience.

In my opinion, AMD have pretty much dropped support for GCN 1.0 cards.
Can't use them for ROCm or Blender for example.
Just let me find the 7970 thread, there was a later driver that seems to work ...

Good luck.  


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Not sure if this is related.

Adrenalin Software BSOD Crash HD 7970 and R9 280 (UPDATED April 1 2019) 

If I were you I would send the 7990 back.
You would be better off finding a single good condition Nvidia GTX 780Ti or higher GPU. 
In my opinion Nvidia have been beating AMD on comparably priced GPU since about 2013.
I have Sapphire HD7970 OC 6GB VaporX and Sapphire R9 280X OC Vapor-X Tri-X. that I can run in Crossfire.
They represent ~ the fastest OC'ed HD7970/R9280x cards available apart from the "Toxic" versions (athough I can run them at "Toxic" GPU and MEM clocks).
The pairing of those two GPU in DX11 Crossfire barely beats a single ASUS GTX780Ti DCUII OC 3GB GPU, which cost less than the Sapphire HD7970 OC 6GB VaporX. 
The Asus  GTX780Ti DCUII OC GPU gets much better driver support from Nvidia. It still runs Blender CUDA, still gets up to date gaming drivers, still works great, stiil gets updated Windows 8.1 64bit drivers and I honestly cannot remember having any PC BSODS or freezes when running that GPU in contrast to the AMD cards.
Thanks.

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lukin
Adept I

Can you see both GPU's in device manager? The 7990's connect together with crossfire bridge cable. No cable no crosssfire

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the 7990 is 2 GPU's in crossfire on one card.  They were not properly crossfiring with one another. 

No bridge cable is required for either the internal crossfire or external to another 7990 or a 7970, there's not even anywhere to attach one.

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So is this a used card you purchased ?

Suppose you read the how-to https://www.amd.com/en/support/kb/faq/dh-018

Ryzen 5 5600x, B550 aorus pro ac, Hyper 212 black, 2 x 16gb F4-3600c16dgtzn kit, NM790 2TB, Nitro+RX6900XT, RM850, Win.10 Pro., LC27G55T..
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terrh
Adept I

OK, Got this working!

- newest drivers (19.4.1)
Just ONE 7990, the crossfire is internal.  Have not tried this with a pair of cards yet

I did several things at the same time and I am not sure if all were required to fix this, and I have also noticed that this is not 100% perfect - sometimes crossfire options don't exist in the "global graphics" page of Radeon settings, and when that is the case crossfire still doesn't work.  But a quick reboot solves it and this only has happened once after solving my main issue.

The things I did to make it work:

Removed and installed the card (doubt this did anything)
Disable CSM in the BIOS
Set windows 10 power settings to "high performance" instead of "balanced" - Suspected it might be turning the 2nd gpu off
Used Afterburner to disable ULPS Again (not sure this mattered either - but it sure might have been it)

This particular card is now working perfectly.    And is surprisingly fast for such an old card. 

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The HD7990 does not have UEFI BIOS so it might be CSM that did it.

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