P5B-Deluxe PCI-express question

This board has 2 PCI-express slots, one is 16x and the other is either 8x or 4x (insignificant which, you'll see why in a minute). I'd like to know if I use the bottom PCI-x slot as opposed to the top if it'll switch to 16x mode?

I'm going to water cool my 8800 in less than a week and it would make tubing a lot easier if I can move it further from the cpu block.

Thanks.

I think with one gfx both slots are 16x, when used in crossfire mode second slot becomes 4x

That is exactly what I wanted to hear. Thanks a ton.

I think the second slot is limited to 4x max. IIRC, the BIOS lists the second port specifically as "Second PEG" or something. I haven't tried this, but I do run a single PCIe 16x card in combination with a PCIe 4x RAID-5 card (PC#1 in my sig), and I can't see any options to set the second PEG slot faster than 4x...

I might be wrong

This is what the official Asus site specs say about the P5B Deluxe:

2 x PCI-E x16 (blue @ x16 mode, black @ x2 or x4 mode)

Sort of confusing to me. First it says 2 x PCI-E x16, then it says (blue @ x16 mode, black @ x2 or x4 mode). Don't know if that means if you use it as Crossfire or if you can use the black by itself as 16X.

Then in the overview it says this:

CrossFire performance optimization offered by C.G.I occurs in Direct Media Interface (DMI) between the P965 Northbridge, which carries one x16 PCI Express slot (x16 PCI Express Lanes), and ICH8R Southbridge, where another x16 PCI Express slot (x4 PCI Express Lanes) resides.

Does sort of sound like the second one is limited to 4X.

I put my 7950GT into the second slot (black) on my P5B Deluxe and it was only working in 4x mode.