Ah, so you're looking for motherboards where the third PCIe x16 slot gets it's x4 lanes from the chipset (and run at 2.0 speed, as opposed to 3.0), leaving the other two slots at x8/x8. There are at least some out there from the looks of things, the key really is to look for ones that list a PCIe 2.0 x16 slot in the specifications (as opposed to all PCIe 3.0
x16 slots), like the ASUS MAXIMUS VII HERO
, GIGABYTE GA-Z97X-UD3H
, and the ASUS Z97-A
(in this one the third slot runs at x2 speed only). Asus seems to be the manufacturer that's most sticking to the chipset powered third slot, so I'd probably suggest taking a closer look at their Z97 range.
Just keep in mind that the third PCIe x16 slot (the one at x4 speed) will likely share it's lanes with some of the PCIe x1 slots or M.2 slots on the board, so if you're planning to use any of those you'd best read the specifics for the motherboard you want to buy to determine what slots can be used at the same time (which things share with which varies quite a lot).