Radeon 2900XT CF Performance Issues (Old I Know)

Hey guys think i already know the answer to this but need some straight forward answers thanks.

As you can see from my signature i currently have a GTX260 216 GPU as my main GPU but my computer originally came with two 2900XT 512MB. For a bit of fun i decided the other day to put them back in to see what there performance would be with updated drivers.

I was very suprised in 3Dmark06 the highest score my rig got with the GTX260 216 was 15039 with a single 2900XT is was 11000+ with the second card enabled in CF the score went up to 15589 which is higher then the GTX260 216.

So i decided to play some games. .as usual with these two cards most games did not like AA being enabled. But my biggest concern is COD4 not a demanding game at all and in single card mode no problems maxed out 4xAA sorted but when CF was enabled the game became laggy which i dont understand as i believe from benchmarks that this game likes Dual Graphics.

Now to my question lol as you can see i have a Asus P5K Premium motherboard which supports CF but when CF is enabled one of the PCI-e Slots is a full 16x the other is only 4x i know its not that good but when i bought my PC this was the 2nd best motherboard from Asus with Intel and CF support.

Is it the case that the 4x lane is not enough to get the data through quick enough causing the issue? That would of been my first guess but with the obvious increase in 3Dmark06 performance and my Source Engined Games (Orange Box) im not so sure.

Any help with this would be great thanks alot

Hey guys think i already know the answer to this but need some straight forward answers thanks.

As you can see from my signature i currently have a GTX260 216 GPU as my main GPU but my computer originally came with two 2900XT 512MB. For a bit of fun i decided the other day to put them back in to see what there performance would be with updated drivers.

I was very suprised in 3Dmark06 the highest score my rig got with the GTX260 216 was 15039 with a single 2900XT is was 11000+ with the second card enabled in CF the score went up to 15589 which is higher then the GTX260 216.

So i decided to play some games. .as usual with these two cards most games did not like AA being enabled. But my biggest concern is COD4 not a demanding game at all and in single card mode no problems maxed out 4xAA sorted but when CF was enabled the game became laggy which i dont understand as i believe from benchmarks that this game likes Dual Graphics.

Now to my question lol as you can see i have a Asus P5K Premium motherboard which supports CF but when CF is enabled one of the PCI-e Slots is a full 16x the other is only 4x i know its not that good but when i bought my PC this was the 2nd best motherboard from Asus with Intel and CF support.

Is it the case that the 4x lane is not enough to get the data through quick enough causing the issue? That would of been my first guess but with the obvious increase in 3Dmark06 performance and my Source Engined Games (Orange Box) im not so sure.

Any help with this would be great thanks alot

Timbury

Yeah im using the two bridges and six and four pin from the PSU for both cards. Tested each card seperately to see if one was faulty both run the same score in 3Dmark06 so not that either.

Might give that a go sounds wierd though :) Does it matter which way the bridges are facing?