Intel 955X Chipset and Crossfire Question

[Arthalen]

Done a lot of research into this and I was wondering if anyone has managed the 'cable-less' approach to Crossfire on this chipset?

I have the Asus P5WD2 non-premium board, updated with latest bios that potentially supports Crossfire. I've read an article on DigitLife that shows the chipset running older X850 cards in a proper master/slace configuration.

However, just got hold of a X1900GT card, and want to run it in Crossfire on my current motherboard.

So:

1) Does anyone know if Cabless crossfire works on this motherboard?
2) Has anyone actually managed to get Crossfire working on a pair of X1900GT's ?

I've done so much searching my eyes are now gone completely google'd

 

[Arthalen]

No one have any idea then ?

 

[infrared]

both cards would allow it, and i don't see a reason why it wouldn't work.

Crossfire works fine on the board, but i've only tried it with my x850's, which don't support cableless crossfire, so i can't really answer your question. It's no real loss if it doesn't work though, just use the dongle

 

[Arthalen]

First, thanks for the reply.

I do know that Crossfire works on the board I have, just wondering about cableless crossfire in particular, as I see no point at all in going for my current X1900GT and a X1900 Crossfire master!

I just want to run a pair of X1900GT's in software crossfire on my board ... I wish someone could answer this, I think I have this posted in about 8 different sites now ... with no answer

 

[infrared]

Wow, that sucks. I'll see if i can track someone down with the same hardware and see how they got on.

The problem is with cableless crossfire on this board is the 4x pci-e on the 2nd card. Using the crossfire dongle means that it isn't really a bottleneck, but if there's traffic flowing both ways through it, you might end up maxing the slot out, and getting pretty poor performance.

Anyway, i'll see if it can be done

 

[Arthalen]

Wow, that sucks. I'll see if i can track someone down with the same hardware and see how they got on.

The problem is with cableless crossfire on this board is the 4x pci-e on the 2nd card. Using the crossfire dongle means that it isn't really a bottleneck, but if there's traffic flowing both ways through it, you might end up maxing the slot out, and getting pretty poor performance.

Anyway, i'll see if it can be done

Thanks for the help. I found this article on Digitlife here thats shows the performance difference of 16x\4x and 8x\8x Crossfire with the top end X850's, and there is a anywhere between a 1-4fps difference - so nothing to worry about their I think.

As for raw output of the cards, I tested my Card in both the 16x and 4x slots with 3DMark and got some interesting results. I'll copy them in here:

I swapped my card over to the 4x lane and ran all 4 3DMark tests.

Under 16x PCI-Ex:
2001 - 27462
2003 - 15504
2005 - 8984
2006 - 4576

Under 4x PCI-Ex
2001 - 25502 = 7.14% Output loss over 16x
2003 - 13623 = 12.05% Output loss over 16x
2005 - 7738 = 13.87% Output loss over 16x
2006 - 4122 = 9.92% Output loss over 16x

For saying the slot has 1/3rd the bandwidth, an avergae of 'around' 10% framerate loss looks pretty appealing for Xfire without a motherboard upgrade.

So, yes, there is going to be some impairment, which I expected, but not to the degree that getting another X1900GT would be pointless.

But I just need confirmation on whether the 955x chipset will do software Crossfire with X1900GTs!!!!!!!!!!!!!

 

[infrared]

I asked over at Extremeoverclocking, and they said the same thing. Theoretically it IS possible to enable cableless crossfire, but the 4x pcie link is only enough for regular crossfire, since you would have double the traffic without the dongle.

You could always try it, but you might be a little dissapointed. What's so bad about having the dongle anyway?

 

[Arthalen]

thanks for the info find Infra.

Its not a case of wanting the dongle or not, I just dont want to buy a X1900 Master card to crossfire my X1900GT. Far cheaper to just get another X1900GT, especially here in the UK.

So, it is possible or not ?

 

[b1lk1]

I have researched this for the past month and so far it is not possible. THe highest possible is X1800 GTO and even then there are people having issues getting it to work. And the performance would suffer greatly on the 16x 4X motherboard considering the main requirement for dongleless cross fire to operate is 16X 16X. It won't work.

 

[Arthalen]

Hi,

Just wanted to let you all know, Ive managed to get another X1900GT and it works perfectly well in Crossfire on my 955X based motherboard with Catalyst 6.9!

Cheers,

Arthalen