We are considering getting a new 5860 workstation. We need to install two PCI cards (PCI x4 and x8). The x8 card is a bit larger in overall size, so I am concerned whether some slots may not fit in. The 5860 has five PCI slots with 2 x16 and 3 x8. Based on the image of the motherboard, I am sure that this is how slots look like:

One of the x8 is described as x4 electrical. Does anybody share information on which slot is x4 electrical?