ASRock X99 Extreme6/ac Motherboard Review

Calculated Value And Final Analysis

The X99 Extreme6/ac costs around $15 less than Asus' X99 Pro, and the largest hardware specification differences are ASRock’s inclusion of dual firmware ROMs (worth about $5-6 after mark-ups), rather than Asus’s included USB Flashback ASIC (worth around $20, according to company representatives). If we take everyone at their word, it sounds like both manufacturers are using the same formula to calculate value. And, because the $40 Wi-Fi card and $5 antenna would need to be purchased separately for the previously-tested ASRock/Gigabyte/MSI models, it looks like anyone on a wireless network gets similar value between those cheaper boards and the 802.11ac-equipped X99 Extreme6/ac. A failure to account for the worth of these features results in a chart that favors whatever is cheapest:

All of those comparisons assume that, apart from a few added features, all of the boards shown are equally desirable. The problem for ASRock’s X99 Extreme6/ac’s is that it faces some of the same slot issues as Asus’ X99 Pro. Plug in three graphics cards on a top-end CPU, add a PCIe-based M.2 SSD, and watch the third card disappear. Use a cheaper CPU with an SATA-based M.2 SSD, and the third card appears but can’t be configured in SLI. Meanwhile, the uppermost PCIe 3.0 x16 slot, which could have donated a few lanes to overcome those issues, doesn’t because it doesn’t have the necessary pathway switches.

Leaving out the switches needed to make the X99 Extreme6/ac run three graphics cards plus a PCIe SSD sounds a little like watering down Champagne with beer. But perhaps I’m being too elitist about these things. After all, an enthusiast can choose to install an SATA-based M.2 card instead, even though the SATA interface is only attached to one 6Gb/s port. Anyone who’s willing to sacrifice that much storage performance is probably also willing to buy a cheaper CPU, and then the third slot runs into the SLI exclusion for four-lane slots.

Remember, those pathways switches are pretty cheap. Both Gigabyte and MSI use them to enable three-way SLI with cheaper 28-lane CPUs on cheaper motherboards. MSI even allows builders to add that lane-consuming PCIe 3.0 x4 SSD while keeping four slots active. Heck, the X99S Gaming 7 allows builders to use a cheaper 28-lane CPU with three-way SLI and a x4 SSD, simultaneously, in an x8/x8/x8/x4 configuration. Of course that board doesn’t have a slot to install a matching 802.11ac Wi-Fi module.

Since ASRock includes wireless networking, I could compare it to the similarly-designed Asus X99 Pro. The X99 Pro costs $15 more, but hardcore overclockers will probably find value in its overclocking advantages. The X99 Pro has identical PCIe 3.0 configuration issues. And while I panned the X99 Pro’s PCIe 2.0 conflicts, the 16-lane slot that causes those conflicts becomes compliant in x1 mode. ASRock’s slot is PCIe x1 anyway.

The X99 Extreme6/ac is a nice motherboard with a few minor flaws that will probably affect fewer than half of its potential buyers, yet anyone who can live with its flaws will find those same flaws, along with better overclocking, in Asus’ X99 Pro.