Asus P8Z68-V Pro B3 + RAID on second PCI-E slot

First of all, make sure you get the Pro/Gen3 model because it's the same price (at least on newegg) and it will let you upgrade later if you want. I don't know that much about RAID cards. However, the Pro has three PCIe x16 slots. If you're using the first two then yes, both will be at x8. If you use the first for the vide card and the third for the RAID card then you'll be at x16 on the video card and x4 on the RAID card. If your RAID card actually needs x8, though, you'll have to put it in the second slot and use x8/x8.

Can I ask why you are using a RAID card? The motherboard can do RAID, although higher end RAID cards do a better job. It's a bit unusual to have a high-end RAID card in a mid-range motherboard, though.

Hi Danraies,

thanks for your quick answer.
I am looking to install a ServeRAID-BR10i with some SSDs.

The user guide says that it will scale down to x4 from x8.
http://download.boulder.ibm.com/ibmdl/pub/systems/suppo...
With 4 PCIe lanes it gets 2GBps and with 8 PCIe lanes it get 4GBps. If you're ok with x4 then the third slot will still let you use your graphics card at 16x. If not then you'll have to use both at x8. Higher-end motherboards will let you use x16/x16 mode, also.

Thanks for your answer.
Probably I'll buy x4 PCI RAID adapter to maximize the speed of the slot+card (...like LSI 9211-i4)

It's definitely hard to find RAID controllers that are both high quality and affordable.