Crossfire 4870x2 problem...

[GuardiaNGR]

Hello,
First of all I should state that i am totally dissapointed by ATI for their Crossfire platform. I don't know about SLI since I haven't used it but at this time i totally regret my decision to buy two ATI cards instead of two nvidias...

So, here's my problem. Recently I noticed that my 1 week old crossfire doesn't perform well. I first noticed it with Modern Warfare 2, some sluggish movement here and there and I was amazed. I turned it off and with one card active it's perfect.

So after that I decided to check my 3dmark Vantage and i almost cried...
crossfire disabled
gpu:12242
cpu:17994

crossfire enabled
pgu:12180
cpu:18046

I am searching the whole internet since then to find a solution but i haven't come up with something. My specs are
Intel Core i7 2.8GHz LGA1156
4GB DDR3 1600MHz GSkill
PSU Thermaltake 1200watt
mobo ASUS P7P55D LE
2x ASUS 4870x2
Windows 7 Ultimate x64 EN

I have the latest Catalyst installed (9.11) and my pc came from a clean install of win7. The first card is on pci-e x16 and the second on pci-e x4. Please any help would be greatly appreciated!!

 

[dguy6789]

You shouldn't be running a 4870x2 on a 4x PCI Express slot.

 

[YBS1]

Another thing, make sure the Catalyst AI advanced setting is enabled in your control panel as well. Supposedly having this setting disabled doesn't allow crossfire to work properly though I've never tried it just to confirm.

 

[dflynchimp]

You shouldn't be running a 4870x2 on a 4x PCI Express slot.

this. the card running in 4X pci-e is forcing the other one to run at 4X as well versus 8x, effectively halving the bandwidth to each card. You need to find a motherboard with 16X -> 8x+8X

 

[Rifter]

what they said, what did you expect out of a x4 slot? those cards need 16x slots, 8x min.

 

[GuardiaNGR]

Thanks for the quick replies, i'll try to get on my hands another mobo with x16 and x8 pci-e and try it out. thing is that no one mentions that and what i have already found at my local market is x16 and x4 boards.

i think with this one i will be ok http://www.e-shop.gr/show_per.phtml?id=PER.522755 (site is in greek language but you can figure out the numbers).

thanks again for the replies, i will get back with the results, i hope that this is the problem...

 

[lavaheadache]

OP, I find that if I'm not using vsync with my crossfire x setup my frame rate seems slower than the numbers suggest due to microstutter. Give it a try

 

[GuardiaNGR]

http://www.asus.com/product.aspx?P_ID=j02KziJq95KbCQNm&templete=2

I've ordered this one, i hope that's the case and my problems are solved although i doubt it. My 3dmark scores are low even with crossfire disabled and the first card running at x16 pci-e which it shouldn't be the case.

 

[Wogdog]

Maybe pull the other card in the 4x PCIe slot, sometimes with the other 4x PCIe slot occupied it hurts the bandwidth one the main 16x PCIe slot. Even if you don't have xfire on.

 

[nitromullet]

http://www.asus.com/product.aspx?P_ID=j02KziJq95KbCQNm&templete=2

I've ordered this one, i hope that's the case and my problems are solved although i doubt it. My 3dmark scores are low even with crossfire disabled and the first card running at x16 pci-e which it shouldn't be the case.

Being able to run your dual 4870X2s at 8x/8x should help over what you currently have, but it still isn't ideal.

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3634&p=9

 

[GuardiaNGR]

Being able to run your dual 4870X2s at 8x/8x should help over what you currently have, but it still isn't ideal.

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3634&p=9

So, in other words don't even bother with Crossfire or SLI? Btw i changed my cards aswell, gave them back and waiting for two 4890s, should i get them or just get one of em?
i am a little hesistant over my experience with crossfire so far...

 

[Voo]

So, in other words don't even bother with Crossfire or SLI? Btw i changed my cards aswell, gave them back and waiting for two 4890s, should i get them or just get one of em?
i am a little hesistant over my experience with crossfire so far...

Well you don't get the same performance improvement from a 1156 board as you'd get with 2 16x, but it's still an improvement..

 

[CitanUzuki]

so its Ati's fault you are using the product on an insufficient mobo?

 

[TemjinGold]

Why are you so bent on crossfire anyway? Why not just pick up a 5870 and be done with it?

 

[SolMiester]

Why are you so bent on crossfire anyway? Why not just pick up a 5870 and be done with it?

this!!

 

[nitromullet]

Why are you so bent on crossfire anyway? Why not just pick up a 5870 and be done with it?

Yeah, this is probably the best advice for someone with a P55 mobo.

 

[lavaheadache]

My tri fire setup is on a dual 8x board and let me tell you it hauls ass

 

[nitromullet]

My tri fire setup is on a dual 8x board and let me tell you it hauls ass

The OP was running the second 4870X2 in a 4x PEG slot. That's twice the gpus on half the bandwidth compared to a single 4870 in an 8x PEG slot.

Since he appears to be buying new, the best recommendation is to opt for a single 5870 which also hauls ass.

 

[Enigmatic]

Yeah, 4870x2 and x4 PCI-e is just a bad bad combination. (This one of the reasons I went AMD, got a decent price on a 790FX and have x16x16 PCI-e lanes). Sucks that you'll have to shell out for a new mobo to make sure those cards aren't bandwidth constrained.

 

[GuardiaNGR]

Bleh, I just wanted to experience Crossfire or SLI, chosed the first one not because I am a fanboy or sth but because ATI atm have the best products and the price ratio is outstanding (plus at my market there seems to be something wrong with nvidias coz i couldn't find anything good to compare).

Anyway, I'll keep the new mobo with x8/x8 in case i want to utilize it in the future, i canceled everything else and waiting for a Saphire 5870. I must admit that i'm already at the verge of getting two of em but if i am going to bottleneck them with the x8 pci-e then i will just wait for my next upgrade to get a cpu and a board with x16/x16

I just hope everything will work as they supposed to this time!