Crossfire performance

[Jackaby]

Recently upgraded from a single Sapphire HD 5850 to 2x 5870 Vapor-x's.

I now run BFBC2 at much higher graphics settings and with no issues, but when I booted up Fallout: NV it was almost unplayable. Out of curiosity I disabled Crossfire and and reloaded Fallout and it's running at Ultra high with no performance dips.

Also tried Assassins Creed 2 and it seems to also be working better with the single card - bummer.

System specs are:

Intel i5 750: stock 2.67Ghz
2x 5870 Vapor-x's
8GB Corsair Dominator 1600Mhz ram
Asus P7P55DLE Mobo
WD caviar green 1tb 7200rpm
Corsair 850watt PSU

Any advice would be greatly appreciated.

 

[Jackaby]

Yup latest drivers are installed. I believe on a tech site I saw that the second PCIE slot at default ran at x4 but could be edited in the bios to run at 16x

 

[Jackaby]

Installed the Application Profiles ?

Application profiles?

 

[Jackaby]

http://sites.amd.com/us/game/downloads/Pages/downloads.aspx

Can't say I noticed that, but I do have CCC 10.11 full suite installed as only upgraded the cards the other day. Starting to think it's just the damn mobo.

 

[Jackaby]

You looked at my thread Jackaby?

Yup, guessing I may have to buy a new motherboard with 2x 16x pcie slots. ****.

 

[Jackaby]

If anyone could reccomend me what they think is the best value for money mobo that has 2x pcie 16 slots that would be great.

However looking at this link of my mobo http://www.asus.com/product.aspx?P_ID=e7Zic83PvQSr80Lm&templete=2 if you click on specifications it states that it does have 2x 16x PCIE slots - just one of them is running at 4x.

 

[Jackaby]

Fallout NV and Assassins creed 2 are both flawless on each card individually. But xfire renders new vegas unplayable and some big unpredictable lag dips on assassins creed 2.

Must just be the x4 pci that's harshly bottlenecking the first card.

 

[Jackaby]

http://www.overclockers.co.uk/showproduct.php?prodid=MB-389-AS&groupid=701&catid=5&subcat=1495 - Just been checking this mobo out and was wondering if you guys could give me any feedback on it?

Only think that worries me that in product description it says " Users can flexibly switch between full-speed PCIe x16 mode for their graphics cards and IO Level UP for rapid data throughput. "

 

[Jackaby]

Thankyou mate, absolute life-saver