X99 Extreme3 Layout
ASRock cuts the X99 Extreme3’s cost in places that many value-seekers won’t notice or care much about, such as the inclusion of only four memory slots and no PCIe pathway switches. But that second point brings us to the third catch when it comes to building with the Core i7-5820K: it only has 28 PCIe 3.0 lanes, and the lack of pathway switches leaves the top slot stuck in x16 mode. Dropping the center slot to eight lanes at the CPU level, there are only four PCIe 3.0 lanes left. And without even more pathway switches, ASRock dedicates all four of those lanes permanently to the Ultra M.2 interface.
That means the third slot is just a tag-along, using half of the lanes from the X99 PCH’s PCIe 2.0 controller. Four lanes on a x16 slot isn’t enough to extract full performance from a modern graphics card, yet the firm still calls the X99 Extreme3 a three-way CrossFire-capable board. Nvidia wisely limits the X99 Extreme3 to two-card arrays. ASRock banks on the notion that value-oriented buyers won’t need three-way SLI, and it’s probably right. On the other hand, we’d hate for an unwary builder to make the mistake of thinking the board must support at least three-way SLI after seeing the term “Quad SLI” in marketing literature. “Quad” refers exclusively to two dual-GPU cards.
Second in marketing value to the Ultra M.2 slot that budget-minded builders probably won’t use, the X99 Extreme3’s socket-mounted dual-BIOS is the biggest feature that they might want to take advantage of. ASRock completely dodges its competitors' auto-switching issues by using a jumper to select between firmware one and two, adds an LED next to each IC to let you know which one is active and even sells replacement ICs to anyone determined to corrupt both ROMs.
ASRock was first to implement Intel’s USB 3.0 front-panel header (way back when it was still a proposal), and still dignifies the standard by placing it front-and-center where it won't conflict with any expansion cards. Additional conflicts are avoided by pointing all ten SATA connectors forward, leaving only the front-panel audio and USB 2.0 cables to interfere with a third graphics card. Not that most people would want a graphics card in the third x16 slot anyway.
The front-panel HD Audio connector is found all the way in the back corner, about an inch too far back for the cables of some cases. That'd really be the case manufacturer's fault though, since Intel specified this location back when it was called (with some pin definition differences) AC'97. Fan connectors are spread out more conveniently, with the X99 Extreme3 sporting two four-pin (PWM) and four three-pin interfaces.
In considering the enthusiast market, the X99 Extreme3’s biggest weakness might be its inclusion of only two SATA cables. The added PCIe two-drive power cable is a nice touch, though, as it connects to the motherboard to allow a remote power-on feature called ASRock HDD Saver.
X99 Extreme3 buyers also get a two-card SLI bridge.