SAS/RAID Adaptec on Rampage 2 Extreme?

[Labdog]

hello,

a little hardware question

i have a Asus Rampage 2 Extreme motherboard which contains 3 pci-e slots 16x-16x-??x

i have 2 pci-e slots used by 2 gtx280 graphic cards in SLI

is it possible to have in the third pci-e slot an adaptec 5405 8x to do raid 5 with 3 ou 4 hard disks

in that way, what is the speed of this third pci-e slot ? 8x, 4x, less?

and also i would like to know if my 2 graphic cards stay in 16x or if the speed of the second card fall down to 8x?

its weird because i see that specification:

"3 x PCIe2.0 x 16 slot, supports x 16, x8, x8, or dual x 16 speeds"

at last, what the impact on the SLI performances?
because of the SLI, i will pass from 16x-16x-1x to 16x-8x-8x.
is someone know the SLI performance difference?

is the SLI saturate the bus in 16x-16x? in that case there will be a performances fall...

edit: i heard there is maybe compatibility problem when we mix graphic cards & non graphic cards in that slots. is that true?

thanks

 

[heymrdj]

The slots holding your two cards will run at 8x, while the slot you put your RAID card in will run 16x. This is typical of even just two slot boards. Almost all of them are 2 8x slots, or 1 16x slot.

 

[Labdog]

no more help?

 

[PCTC2]

You should be fine with the RAID card.
Depends on the resolution you play and what games, but SLI profiles are pretty good these days so you might see a tiny performance drop as these cards near saturate a 8x lane, but you will be running in "16x-8x-8x".

 

[Labdog]

do you know how much the performance drop is? 5%?