Intel's X299 platform offers a maximum of 44 PCIe 3.0 lanes from its accompanying CPUs, but even that might not be enough for the most demanding builders. Enter Gigabyte's X299-WU8 motherboard. This mobo uses not one, but two eye-wateringly expensive Broadcom PEX 8747 PCIe switches under its chipset heatsink to provide all four of its main PCIe 3.0 slots with 16 lanes of connectivity. If you just need to run a lot of single-slot cards, the WU8 can oblige with 16 lanes on its first slot and eight lanes to each of the remaining six PCIe slots on the board.
To provide extra power to whatever expansion cards ultimately occupy those slots, Gigabyte includes a six-pin PCIe connector southwest of the CPU socket. To keep those switches (and the VRM) cool, Gigabyte uses a blend of heat pipes and finned heatsinks that worm their way through the top half of the board. Eight-phase International Rectifier power circuitry provides juice to whatever chip ends up in the LGA 2066 socket.
Cramming every inch of board space full of PCIe slots and heatsinks does involve some tradeoffs. The WU8 only has a single M.2 2280 slot for next-gen storage gumsticks, although it does offer eight SATA ports. We're sure you can find some extra PCIe lanes to plug in an M.2 riser card if you really need more NVMe storage devices. The WU8's back panel offers two USB 2.0 ports, six USB 3.1 Gen 1 ports, and two USB 3.1 Gen 2 ports: one Type-A, the other a Type-C. Dual Intel Gigabit Ethernet ports handle wired networking, and Realtek ALC1220VB audio should provide serviceable sound quality for the discerning listener.
Gigabyte didn't provide pricing or availability info for this board, but two PEX switches don't come cheap. For those who need its unique capabilities, however, the X299-WU8 will likely be worth every penny.