Crossfire PCI-e link speed question

[^Si|eNcE]

I'm curently running an Asrock Extreme6 Z77.

Have a XFX 7970 DD(in PCIE2) and a PowerColor 7970(in PCIE4) in crossfire..

The specs of the board says that xfire will run at dual x8 but when i look in gpu-z(while Render Test is on) it only shows x8 for one.. x4 for the other..

what should i do to get it to dual x8?

 

[royfrosty]

Which pcie slot you using? You are suppose to use the first 16x pcie slot and the 2nd available 16x slot.

 

[^Si|eNcE]

total got 3 pcie slots.. im using the first 2.. the third is a x4 pcie slot..

 

[hlots123]

try swapping the 2 cards around (top> bottom; bottom> top)...

 

[^Si|eNcE]

i've swapped them a couple of times.. each swap requires a cleanup and reinstallation of the catalyst right?
whichever card at the bottom will run @ x4.

 

[royfrosty]

No you won't need to do a reinstall of catalyst .

 

[^Si|eNcE]

but if i do not reinstall.. the drivers for the cards are not "Updated" and it shows up as the "Generic Video" thing..

That aside.. what can i do to make both cards run at x8?
i've gone through the bios settings seems like i can only select which gen for the pcie but not the speed..

 

[shadow84]

Do you have any pcie card for lan, soundcard installed in the most bottom pciex16 slot?

 

[shadow84]

You can try update your mobo BIOS as well.

If it still cant work, then best to RMA liao...

 

[devilwahaha]

but if i do not reinstall.. the drivers for the cards are not "Updated" and it shows up as the "Generic Video" thing..

You can try going to your device manager in Control Panel and under Display Adapters right click and Scan for hardware changes.

 

[hlots123]

last time i swap my cards around, no need to reinstall catalyst.
did u try looking in bios settings to see if pcie link width for bottom slot was accidentally set to x4? look thru adjacent settings as well (and ref manual).

i've swapped them a couple of times.. each swap requires a cleanup and reinstallation of the catalyst right?
whichever card at the bottom will run @ x4.

 

[^Si|eNcE]

Do you have any pcie card for lan, soundcard installed in the most bottom pciex16 slot?

only 2 pcie slots in use.. for both the 7970s..

 

[royfrosty]

I know is strange, but are you sure your board is asrock z77 extreme 6?

From what i know, not all z mobos support x8x8

 

[shadow84]

Lol.. check with cpu-z

 

[^Si|eNcE]

I know is strange, but are you sure your board is asrock z77 extreme 6?

From what i know, not all z mobos support x8x8

im sure it's a z77 extreme 6. says so on cpu-z as well as printed on the board...

according to their website it states that z77 does dual x8..

 

[shadow84]

im sure it's a z77 extreme 6. says so on cpu-z as well as printed on the board...

according to their website it states that z77 does dual x8..

Sad to sae, u need to rma le.... ur pci-e lanes nt working properly.

 

[^Si|eNcE]

Sad to sae, u need to rma le.... ur pci-e lanes nt working properly.

>_<! kkz.. thanks..

 

[shadow84]

An unlikely chance but if u have a fren who uses Z87/77/97 mobo that supports xfire in x8 x8, test your gpu with it. make sure its nt gpu problem.