Crossfire and M4A89TD-Pro/USB3

[Kileak]

Hi everyone, been a while since I've posted but I've been reading up

Anywho, so I got this nice Asus motherboard last week and installed two 5770s on it but I just realised tonight that both Catalyst and GPU-Z report one card running at PCIe 16x while the second one is at 8x...

Taken from Catalyst's Graphic Hardware view:

...
Linked Adapter
...
Maximum Bus Setting PCI Express 2.0 x8


I was under the impression that the 890fx chipset had dual 16x slots, anything I'm doing wrong here? Or did I just misunderstand something?

I've read elsewhere "clean off contacts" but the cards are brand new and there wasn't anything on the contacts.

Now I know the performance drop is most likely negligible and the system is currently running very well but still, I figure I paid for this mobo thinking it had that functionnality, why isn't it working as intended...

 

[QuietIce]

The 790/890FX chipsets can and should run at 2x 16-bit.

I'm not sure what's going on with the ASUS boards. Another guy is having trouble getting his single card running x16 on an ASUS M4A89GTD (at least, according to GPU-Z), which is the 890GX chipset. It can't run 2x 16-bit but it should run 1x 16-bit. I'm wondering if ASUS wired these boards different somehow and the detection programs are maybe reading them wrong. I know there have been some other monitoring issues with recent ASUS boards so who knows ...?

 

[migidarra]

From what I have read and seen, the difference in x16 and x8 on a graphics card is roughly 2%. However I would just try and call asus customer support to see. Regardless of performance if i buy an item that says 1000 awesomeness I want 1000 awesomeness not 980 awesomeness. Anyway keep us updated!

 

[Kileak]

Solved!

For some unknown reason, taking both cards out and switching them slots solved the problem. Catalyst is now reporting both cards at 16x. Wheee!

I figured I'd have a look at both of the cards up close and check contacts to be sure but there wasn't anything. Still, maybe re-seating them in different slots allowed the contacts to... contact better...

 

[TonyMc]

Solved!

For some unknown reason, taking both cards out and switching them slots solved the problem. Catalyst is now reporting both cards at 16x. Wheee!

I figured I'd have a look at both of the cards up close and check contacts to be sure but there wasn't anything. Still, maybe re-seating them in different slots allowed the contacts to... contact better...

Really? Because according to the specs two cards will only run @ x8 x8. One card in blue, dummy card in grey will produce the blue slot to run @ x16.
I'm the other guy Quietice was referring to. I'm having an issue where the blue slot will not run @ x16 with dummy card or at least it's not reported that way in GPU-Z.

 

[MacClipper]

Really? Because according to the specs ...

His is a higher end 890FX TD mobo while yours is the mid range 890GX GTD, not quite the same although the names look similar.

@Kileak, poor contact is quite a common cause for such issues.

 

[TonyMc]

His is a higher end 890FX TD mobo while yours is the mid range 890GX GTD, not quite the same although the names look similar.

@Kileak, poor contact is quite a common cause for such issues.

Oh. I miss read that.

 

[MacClipper]

Well, nobody's perfect.

 

[Kileak]

poor contact is quite a common cause for such issues.

Didn't think they'd be that fussy!

 

[SeanOMatic]

I am willing to bet it wasn't even that the cards needed to be switched. You know the Crossfire bridge cable? They are troublesome.