CrossFire 16x and 4x - anyone tried this?

[jmp_78]

My Asus P7P55D has 2 PCIe slots, and I currently use the first one at 16x to run my 5850. I've never thought about CrossFire as the 2nd slot runs at PCIe 4x, and I was told a while back this would be a major problem.

However I've been looking into it again, and now found review sites that suggest that 16x and 4x together are not so bad - the second card loses between 5% and 10% performance.

Basically - does anyone run this, or at least tried it?

Would really appreciate some thoughts on this one guys - thanks very much

 

[Mr Krugga]

If the board supports Crossfire then you'll be able to do 4x/4x Crossfire but the cards will lose a lot of their potential. It won't be a problem at lower resolution though.

There's some problem with my other 5850 in the second rig and since it can't fit in the first PCI-E slot due to HDD cages in the case being too close to the graphics card, it has to run in the lower slot that should be 8x capable but for some reason it only runs at 4x (have yet to establish whether it's the card or the mobo that's playing up).

Anyway, there is no evidently noticeable performance loss but it's definitely there.

I'm sure Tom does the scaling tests fairly regularly but it could be another website that I've got on my mind now.

Damn laptop touchpad.

 

[joxang]

My Asus P7P55D has 2 PCIe slots, and I currently use the first one at 16x to run my 5850. I've never thought about CrossFire as the 2nd slot runs at PCIe 4x, and I was told a while back this would be a major problem.

However I've been looking into it again, and now found review sites that suggest that 16x and 4x together are not so bad - the second card loses between 5% and 10% performance.

Basically - does anyone run this, or at least tried it?

Would really appreciate some thoughts on this one guys - thanks very much

Yep tried on a P55 board. You may lose 5-10fps depending on the gpus, but nothing drastic. x16 x2 is another story .

 

[cmndr_andi]

Looking at this article there is a reasonably significant performance loss (albeit not crippling and certainly better than a single card), but what worries me most is the reports that you get microstutter when you run high-end cards at this restrictive bandwidth.

 

[jmp_78]

Looking at this article there is a reasonably significant performance loss (albeit not crippling and certainly better than a single card), but what worries me most is the reports that you get microstutter when you run high-end cards at this restrictive bandwidth.

Microstutter is something I'm aware of, but luckily never experienced. In fact I can't even picture what it is - shouldn't complain I guess! Thanks for the heads up