Intel's X99 chipset and Haswell-E processor represent the most devastating combo in the desktop division. The chipset opens with a flurry of USB and SATA ports, plus a dash of M.2 and SATA Express. Then comes the thunder: a 22-nm CPU with quad DDR4 memory channels, up to eight Hyper-Threaded Haswell cores, and as many as 40 PCIe lanes. No other desktop duo comes close to that kind of firepower.
One's options are somewhat limited on the CPU front. Intel sells just three versions of the chip, and only the top model has all eight cores enabled. There are, however, myriad motherboard choices. Over 40 X99 boards are listed at Newegg, each one with a slightly different personality.
We've already tested Asus' X99 Deluxe and its pared-down X99-A cousin, plus Gigabyte's rave-tastic X99-UD4, and we're not done yet. Today, the spotlight turns on another contender for the heavyweight belt: MSI's X99S MPower.
Priced at $284.99, the MPower sits smack in the middle of the X99 range. And it continues the trend toward increasingly blacked-out motifs. Only sparing splashes of canary yellow interrupt the stealthy theme, though white LEDs embedded in the underbelly emit a ground-effect glow when the board is powered on. MSI includes a firmware switch for full stealth mode, which extinguishes all the onboard lighting save for the POST code display.
Although the MPower sticks to the standard ATX footprint, its selection of power connectors is a little unusual. In addition to sporting the 24-pin primary and 8-pin auxiliary 12V connectors present on most X99 boards, the MPower has a second auxiliary 12V plug meant for four-pin connectors. As far as I can tell, the extra input is supposed to be used in addition to the eight-pin connector rather than instead of it—for moar overclocking, of course.
Overclocking requires beefy cooling, which is somewhat at odds with Haswell-E's crowded socket. There isn't much room for oversized coolers between the VRM heatsink, memory, and closest PCI Express slot. Since we can't test compatibility with every combination of components, we've provided some clearance measurements:
Note the two sets of memory clearances. The slots closest to the socket only need to be populated with eight-DIMM configs, while the second row is used by the four-DIMM setups we'd expect most folks to be running.
The closest potential obstruction is actually the VRM heatsink, but it's shorter than standard-height DIMMs, so it's unlikely to interfere with aftermarket coolers. As with most modern motherboards, memory modules with tall heat spreaders represent the biggest threat.
While we're discussing clearances, we should visit the MPower's expansion slots, which are somewhat awkwardly spaced for CrossFire and SLI configs.
The first and second x16 slots from the left are used for dual-card setups. Their close proximity precludes triple-slot coolers, and more importantly, it leaves no breathing room between double-wide duos. Cards installed in the second slot will also heat up the area around the M.2 storage slot, which could trip the thermal throttling mechanism in some mini SSDs.
Triple-GPU setups tap into the third or fourth slot depending on the CPU. The fact that Intel offers versions of Haswell-E with either 40 or 28 PCIe lanes makes things a little complicated, so we've mapped out the possible lane assignments in the block diagram below. Click the buttons to toggle between the different CPU configurations.
The third x16 slot is only active with 28-lane CPUs, while the fourth is meant for 40-lane chips.
In an interesting twist, the M.2 slot can switch between four Gen3 lanes in the CPU and two Gen2 lanes in the chipset. The CPU link provides more bandwidth to SSDs that can take advantage, while the chipset connection should offer more robust boot support via Intel's Rapid Storage Technology software. A firmware toggle dictates the source of the M.2 lanes.
As with most 9-series motherboards, the chipset's M.2 link is shared with SATA Express, which leads us nicely to the storage section on the next page.