Haswell-E and its X99 sidekick are easily the most exciting tag team for high-end desktops. The CPU crams up to eight cores into a single socket, and it's backed by quad channels of cutting-edge DDR4 memory. Haswell-E chips also have up to 40 PCIe Gen3 lanes, providing copious bandwidth for multi-card graphics configs and high-speed SSDs. And then there's the X99 chipset, which is brimming with USB 3.0 and 6Gbps SATA ports, plus configurable I/O lanes that can be devoted to SATA Express or M.2 storage.
This duo isn't Intel's high-end desktop platform for nothing.
Enthusiasts who want to get in on the action will need a CPU from the Core i7-5xxx series and a motherboard based on the X99 chipset. There are dozens of compatible boards from which to choose, including Gigabyte's X99-UD4, which is one of the more affordable options around. We've spent some quality time with the UD4 to learn what it does well—and where it falls short. Read on for the scoop.
From a distance, the UD4 gives off a vaguely Dark Knight vibe. The matte black board and low-key aesthetic should nicely blend into the shadowy confines of most PC enclosures.
Don't think the subdued gold accents mean this thing is short on bling, though. The UD4 has extra gold plating on the pins in the CPU socket, DIMM slots, and PCIe x16 slots. According to Gigabyte, this 30-µm gold layer is five times thicker than on "standard" designs. The additional material is supposed to improve corrosion resistance and long-term durability, which might appeal to folks who live in especially humid climates or who swap components obsessively. Seems a little gimmicky to me.
The socket is fed by all-digital circuitry based on a new generation of International Rectifier's PowIRstage hardware. "Server level" Cooper Bussmann chokes dot the landscape along with solid-state capacitors from an unnamed vendor. We're not experts on the minutiae of base electrical components, so make what you will of those upgrades.
Rows of 288-pin DDR4 memory slots flank the socket, offering a home for up to 64GB of memory. Beware of modules with taller heat spreaders; the memory slots are close enough to the socket to potentially interfere with larger aftermarket CPU coolers. We can't test every hardware combination for compatibility, so we've measured a few key clearances to illustrate how much room is available.
The DIMM slots are no closer to the socket than on the other X99 boards we've seen. The clearances for the top PCI Express x16 slot and VRM heatsink are a little tighter, but at least the heatsink is relatively short. Of course, socket clearance issues can be easily avoided by running a closed-loop liquid cooler with a low-profile CPU block. That's what we recommend for Haswell-E builds.
The expansion slots are partly to blame for the crowded socket. They're stacked seven tall, yielding one more slot than on the pricier Asus X99 Deluxe we reviewed recently.
All four of the x16 slots have Gen3 connectivity from the CPU. The first two share 16 lanes that can be devoted solely to the top slot or split evenly between them. The third slot has 16 lanes at all times, while the fourth makes do with x8 connectivity.
CrossFire and SLI configurations are supported with up to four cards, though only when paired with CPUs that have all 40 PCIe lanes intact. Intel limits the Core i7-5820K to 28 lanes, which in turn restricts the UD4 to three-way SLI. CrossFire isn't as picky about bandwidth, so quad-Radeon configs will still work with the runt of the Haswell-E litter.
The spacing provides ample breathing room for larger graphics coolers, including dual-triple-wide setups, which leave the middle x1 slot unobscured. Up to three devices can be stuffed into that gap: one in the x1 slot and two more in the low-slung M.2 sockets to the right. The lower M.2 receptacle has a single-lane PCIe Gen2 link to the X99 chipset; it's meant for mini Wi-Fi cards. Twice the bandwidth is available to the upper socket, whose dual-lane chipset link is reserved for storage devices.
As in most 9-series Intel boards, the M.2 storage slot shares a reconfigurable chipset link with the SATA Express connector and the dual 6Gbps SATA ports embedded within it. This arrangement is officially endorsed for Z97 and H97 chipsets, but it's not validated for X99, and Intel warns that some storage-related functions (likely related to its RST drivers) may not work correctly. Motherboard makers seem confident everything will be just fine.
Counting the SATAe connector, the X99-UD4 has 10 Serial ATA ports. Six of those are available for RAID arrays managed by Intel's drivers, while the remaining four are restricted to IDE or AHCI modes due to limitations associated with the X99 chipset. Drives connected to the non-RAID ports can still participate in arrays managed by the OS or other software, though.
The X99-UD4 lacks auxiliary storage controllers, but it does split the chipset's USB 3.0 connectivity using a Renesas hub. Four of the rear ports are connected through that hub, while the remaining two—and the two-port internal header—enjoy direct lines to the chipset. Too bad Gigabyte doesn't identify which of the rear ports are which.
The company does, however, mark one of the USB ports with white trim. This port is meant for Q-Flash Plus, which can update the mobo firmware using little more than a power supply and a thumb drive. The automated process copies the primary firmware to the onboard backup chip before updating the main one.
Apart from the antenna bracket for M.2 Wi-Fi cards, the rear cluster is fairly conventional overall. The GigE jack is backed by an Intel controller, and the audio is fed by a Realtek codec. There's an amplifier chip for the stereo output, plus a familiar mix of other enhancements, such as audio-specific capacitors, codec shielding, and isolated traces. The left and right output channels are split between different PCB layers to minimize crosstalk, too.
The analog audio output sounds decent to my ears, with no audible hissing or buzzing under load. Realtek's drivers add surround sound virtualization, but they can't encode multi-channel audio for digital output, which limits the S/PDIF port to stereo playback and surround content with pre-encoded tracks.
Gigabyte ships the UD4 with a cushioned I/O shield that's infused with LEDs. The board has extra LEDs, too, and the lighting can be set to flash in time with audio piped through the onboard stereo output. Grab a glow stick, drop a tab of E, and let your dilated pupils take in the show:
I've gotta admit, my inner 16-year-old thinks that's pretty rad. (People actually said "rad" back when I was a teenager—without any irony, even.) The rest of me is happy the lighting can be disabled in the firmware or via Windows software. Pulsing and always-on modes are also available.
In addition to the funky lighting, a handful of other unique twists separate the UD4 from the rest of the pack. The included SATA cables are sheathed in woven housings, just like typical PSU wiring, and there's a bizarro three-to-one splitter for auxiliary 12V power. Gigabyte also defines a wider boundary around the mounting holes to prevent slipped screwdrivers from damaging traces and onboard components. That little tweak was inspired by the RMA department, which apparently sees a lot of surface damage around the screw holes.
Despite this attention to detail, the UD4 lacks wiring blocks to simply front-panel connections. There's no way to boot directly into the firmware interface, either. Gigabyte does offer a direct-to-UEFI switch on some of its higher-end X99 boards, but that feature didn't make the cut for this particular model.
Speaking of the firmware, let's assess the UD4's overclocking and tweaking options...