Asus released the original X99-E WS motherboard back in 2014, and reviewers were fond of its generous expansion options. Given the success of that model, it's no surprise that Asus is updating it for Broadwell-E, with the appropriately-named X99-E-10G WS.
New to this version of the board is an Intel X550AT2 10-gigabit Ethernet controller. That chip and its heatsink rest amidst the I/O cluster. This does take up quite a bit of back-panel port space, but it ensures maximum reliability when using the X99-E-10G's dual 10-gigabit Ethernet ports. In addition to four USB 3.0 and two USB 3.1 ports on the back panel, the board still has headers for four more USB 3.0 and four USB 2.0 ports.
Besides the new high-speed network hardware, this board also drops its predecessor's unloved SATA Express connection for a U.2 jack. Of course, it also has an M.2 socket, with screws for 60mm and 80mm M.2 drives. Both U.2 and M.2 connections are equipped with four lanes of PCIe 3.0 connectivity. Ten SATA 6Gbps ports fill out the board's storage options.
Aside from those changes, the X99-E-10G WS is pretty similar to the original X99-E WS. Like the previous model, the new board uses a multiplexer to spread 64 lanes of PCIe 3.0 across seven x16 slots. That allows the board to support four PCIe x16 connections, or a single x16 and six x8 connections. Asus reinforced all seven slots to prevent users who frequently remove and reinstall cards from damaging the board. Asus says the refreshed X99-E WS will be available "soon" for a suggested price of $650.