The X399 motherboard guide: Threadripper gets a dose of ASUS ROG and Prime

There are two kinds of desktop CPU platforms. The mainstream tier runs from two cores up to eight, and it’s great for gaming and general use. Its high-end sibling takes everything up a level with more cores, more memory channels, and more bandwidth for graphics and storage. A considerable upgrade in every regard, this high-end desktop platform appeals to power users, content creators, and prosumers who want to blur the line between desktop and workstation. AMD’s Threadripper CPU is the latest addition to the desktop’s heavyweight division, and it walks into the ring with an entourage of SocketTR4 motherboards in tow. This guide explains the ASUS and ROG family to help you pick the best X399 motherboard for your high-end desktop or gaming PC.

All of our X399 boards share core DNA that includes one-touch overclocking, refined cooling control, and improved RGB lighting. Yet they each have their own distinct flavor as well. The ROG Zenith Extreme brings Threadripper into the world of premium dream PCs with provisions for custom liquid cooling and 10G networking. With the Strix X399-E Gaming, hardcore gamers can build stylish rigs with power to spare for high-quality streaming. And then there’s the Prime X399-A and its well-rounded foundation channeling the professional side of the platform’s prodigious power. Which X399 motherboard should you buy for your build? Let’s find out.

If you’re interested in other chipsets, don’t miss our motherboard guide for Intel’s similarly extreme X299 platform. We also have guides for standard desktops, including the Intel Z270 and AMD AM4 platforms.

Ryzen gets ripped

With up to 16 CPU cores and 32 threads, Threadripper doubles the computing resources of AMD’s most powerful desktop chips. It’s a musclebound monster hungry for complex video editing, 3D rendering, and heavy multitasking. The power is split between dual dies linked by AMD’s Infinity Fabric. They share a single package that plugs into a new TR4 socket with an astounding 4094 individual pins.

There’s no getting around the fact that Threadripper is huge, but the massive chip makes sense when you peek under the hood and find much more than just a beefy CPU. The accompanying quad-core memory controller doubles the bandwidth available on standard desktops and lets you run a staggering 128GB of DDR4 memory on a single board. Our T-Topology trace layout is optimized to deliver the best signaling with two DIMMs per channel, so you don’t have to dial back the frequency to take full advantage of the capacity.

Bandwidth ripples across every inch of the processor. The PCI Express 3.0 controller boasts 64 individual lanes, 60 of which are available for graphics cards, NVMe SSDs, and other peripherals. To put that into perspective, Ryzen has just 20 open lanes, or a third of the peripheral bandwidth inside Threadripper.

Most high-end desktop chips stop there, but not Threadripper. It incorporates even more I/O with eight USB 3.1 Gen 1 ports that don’t have to share interconnect bandwidth with the X399 chipset. The processor even has an interface for the onboard audio codec. More USB ports are available in its chipset sidekick, which also serves up six SATA ports and PCIe Gen 2 lanes for onboard peripherals like networking.

Bigger engines need better cooling

Threadripper’s hardware adds up to a relatively high TDP of 180W. To improve thermal dissipation for the power circuitry quenching the processor’s thirst, our X399 boards pipe heat from the VRMs to a finned radiator and fan discreetly tucked under the I/O shield. The fan only spins up when necessary, so it’s silent for everyday tasks but responsive when you need a cooling boost.

Processors of Threadripper’s magnitude pair best with liquid cooling, so we’ve equipped our X399 motherboards with everything you need. They offer dedicated headers for pumps and all-in-one coolers, so you can get up and running quickly without fussing over the setup. Our ROG models also have headers for monitoring coolant flow and temperatures, and the Zenith Extreme boasts an extra one reserved for custom monoblocks.

Liquid adornments are complemented by comprehensive fan speed controls capable of managing a full system’s cooling through a single intuitive interface. Our FanXpert intelligence can now adjust each fan’s speed based on the hottest input from a group of configurable sensors, including the GPU diode on compatible graphics cards. This allows the cooling to react to a range of different workloads, like gaming binges that turn your graphics card into a space heater, and complex rendering that lights up all the cores on your CPU.

Tweakers can fiddle with each fan’s response curve and access a full suite of overclocking and performance options. You don’t need to be an expert to tune your rig, though. With a single click, our 5-Way Optimization software automatically configures your cooling and overclocks your processor. The auto-tuner acts like a personalized overclocking service by slowly increasing the CPU frequency and testing stability to find the sweet spot for your chip and cooling. It’s a great way for new recruits to get started and lets veterans establish a quick baseline when overclocking new builds.

So graphics, such SSDs

Bandwidth is a huge part of Threadripper’s appeal. The mother lode of PCI Express lanes stands ready for the multiple high-end graphics cards required for truly cutting-edge gaming and VR experiences. All of our X399 motherboards support three-way SLI and CrossFireX setups, and the Zenith Extreme can call upon a fourth card for record-setting benchmark attempts or an extra jolt of compute power. To protect your investment, SafeSlot reinforces the graphics slots against damage from increasingly heavy GPU coolers.

Threadripper has enough PCIe to easily connect multiple NVMe SSDs directly to the CPU. But it’s not enough to just have a bunch of M.2 slots. The fastest SSDs can heat up under heavy sustained loads, causing performance to drop when you need it the most. To improve thermals, the M.2s on all of our X399 motherboards are either covered by heatsinks or positioned so that drives are in the path of airflow. On top of that, the boards come with U.2 ports for the cabled NVMe SSDs derived from data centers.

With so much bandwidth inside the platform, we had to give our X399 motherboards lots of ultra-fast connectivity to reach outside the box. For external devices, USB 3.1 Gen 2 ports provide 10Gbps links in all the flavors: Type-A, Type-C, and front panel. The Gigabit networking uses reliable Intel controllers, and that’s just the start. The ROG Zenith Extreme takes networking up a notch with not only a wired 10G Ethernet card, but also a wireless 802.11ad module.

Bask in the glow of your creation

The days when PCs looked dull and boring are long behind us. Today’s best DIY rigs are works of functional art in their own right, and our trendsetting styling continues to evolve with the times. The ROG and Prime interpretations of X399 present distinctive monochromatic themes that combine clean lines with a neutral canvas for customizable lighting.

Premium boards need to look the part, so the Zenith Extreme has enough lighting capacity to turn heads. Its onboard highlights and glowing edge lay the foundation, leaving standard and addressable RGB headers to paint the rest of your system. In a subtler twist, we’ve added a LiveDash OLED to the I/O shroud that can show custom logos, small animated GIFs, and system vitals like temperatures, voltages, and frequencies. There’s even a music mode that tracks the audio output.

PC aesthetics were forever changed by the RGB revolution. Instead of just adding more LEDs, we’ve developed a rich Aura ecosystem focused on interoperability and development. With Aura Sync parts from ASUS and our partners, you can synchronize the lighting across an entire PC with just a few clicks. Developers can take control with their own software using the Aura SDK, which will expand to encompass new features and hardware.

Admittedly, we’ve also added more LEDs. But they’re masked behind edges and translucent materials to give off a subtler and more even glow. Following in the footsteps of our Maximus VIII Hero Alpha motherboard, which pioneered the inclusion of RGB strip headers to light chassis internals, our latest ROG models up the ante with new addressable headers. Each LED in an addressable device can be controlled independently, opening the door for more advanced cosmetic and functional displays. The Zenith Extreme and Strix X399-E both have addressable headers, and our partners are working on compatible strips, fans, and chassis.

These are the boards you are looking for

Each of our X399 motherboards is tailored slightly differently, and it shows in the specs. Here’s a rundown of how our Threadripper motherboards stack up. You can click the board names to take a closer look at each one.

The Zenith Extreme is available to pre-order starting today via the retailer links in the table above. The Prime X399-A will be available for pre-order in the coming days, and the Strix X399-E will be available in August.

With the family tree sorted, it’s time for a closer look at each board. The top is as good a place as any to start.

The ROG Zenith Extreme lives up to its name

All-new for this generation, the Zenith Extreme is the flagship of ROG’s AMD motherboard lineup. It comes with all of our latest features, including innovations available only on a select group of top-of-the-line models.

For liquid cooling, the standard assortment of pump and flow headers is augmented by a consolidated connector for monoblocks. With compatible blocks, you can monitor coolant temperatures, flow, and even the presence of leaks over a single cable. That leaves the individual flow, temperature, and pump headers available for a dedicated graphics loop. The accompanying array of onboard fan headers includes one high-amperage option for finger shredders. Plug in the included Fan Extension Card, and you’ve got enough headers to power up to nine fans using the same onboard intelligence.

Although all our X399 motherboards have four PCIe x16 slots hooked up to the CPU, only the Zenith Extreme is designed for that many graphics cards. Its slots are spaced for double-wide coolers if you want to horde GPU power to leave your mark on benchmark leaderboards. On a more practical note, adding a fourth card can further accelerate compute-heavy workloads like 3D rendering and deep learning. To combat GPU sag, we include our ROG VGA Holder, which is strong enough to keep even the heaviest graphics cards horizontal.

Room for up to four NVMe SSDs means you can hit breakneck speeds on all of your drives, from boot disks to scratch space to game libraries. One M.2 slots sits under the chipset heatsink for improved cooling, while the other two ride a DIMM.2 module that plugs in next to the memory slots. After introducing DIMM.2 with the Maximus IX Apex, our engineers developed a second generation with better airflow for the drives, headers for two temperature sensors, and a mount for up to two 50-mm fans.

Our Extreme motherboards are defined by their pursuit of new technology in every area. This is evident in the networking, which includes a 10G add-in card that increases wired bandwidth by an order of magnitude over Gigabit Ethernet. You don’t have to jump to top speed right away, either. The card supports intermediate 2.5G and 5G tiers that work with more conventional cabling. The onboard wireless is a triple-barreled shotgun, with a 1×1 antenna for wicked-fast 802.11ad links, plus a 2×2 setup for dual-band 802.11ac Wi-Fi.

Premium boards need to look the part, so the Zenith Extreme has enough lighting capacity to turn heads. Its onboard highlights and glowing edge lay the foundation, leaving standard and addressable RGB headers to paint the rest of your system. In a subtler twist, we’ve added a LiveDash OLED to the I/O shroud that can show custom logos, small animated GIFs, and system vitals like temperatures, voltages, and frequencies. There’s even a music mode that tracks the audio output.

Another marriage of flash and function is found at the rear, where I/O ports pierce an integrated shield that simplifies installation. The audio jacks are LED-backlit for better visibility behind your battlestation or at dimly lit LAN parties. Along with the usual assortment of SupremeFX onboard sound enhancements, you get HRTF-powered surround effects compatible with VR headsets like the Oculus Rift and HTC Vive.

Unmatched in its class, the ROG Zenith Extreme commands a premium $549.99 USD and $689.99 CAD. Pre-order it for your Threadripper dream build at the retailers listed above.

The Strix X399-E Gaming inspires a new generation

Gaming is more than just playing. There’s a whole world of streaming and broadcasting that has turned it into a form of entertainment watched by millions. A product of this new regime, the Strix X399-E Gaming brings Threadripper’s horsepower to bear on high-quality streaming and complex post-production while keeping one foot firmly planted in hardcore gameplay.

While it doesn’t go to the same lengths as the Zenith, the Strix follows a similar theme. It’s designed to be shown, with multiple onboard lighting zones backed by headers for both standard and addressable RGB hardware. PCs that were once tucked out of sight are now displayed with pride behind tempered glass panels; the Strix lets your build speak with more range than most.

Extra peripherals add to the versatility. A multitude of onboard ports and connectors is bolstered by wireless split between 2×2 802.11ac Wi-Fi and Bluetooth 4.2. In addition to jacking into high-speed wired networks and devices, you can enjoy the convenience of cable-free connectivity.

With support for three double-wide graphics cards and three NVMe SSDs, the Strix X399-E Gaming can easily scale up or down to meet your needs. There’s enough breathing room to run dual 2.5-slot cards like our Strix GTX 1080 Ti–and at a full 16 PCIe lanes per card. Primary M.2 drives get cooling from the chipset heatsink, while secondary SSDs poke out of a vertical slot with that can benefit from chassis airflow.

Ready for cooling in any form, the diverse collection of liquid and fan headers lets you run everything from off-the-shelf AiOs to custom loops. With eight 4-pin headers in total, there’s enough capacity to cover an entire build.

ROG’s latest generation of SupremeFX audio has been tweaked specifically to improve recording quality. Your voice will come through loud and clear whether you’re broadcasting to an audience or discussing strategy with teammates. The newest version of our Sonic Studio software also makes it easier to direct audio streams to different devices, so you can assign game audio to headphones, music to speakers, and video to an auxiliary display with just a few clicks.

Designed for the growing community that defines the gaming scene, the Strix X399-E channel’s ROG’s pedigree to help gaming PCs exceed expectations. It will be available in late August in the US and Canada with pricing to be announced closer to its release.

The Prime X399-A strikes the right balance for prosumers

An oasis in a market flooded with gaming everything, the Prime X399-A dresses Threadripper in more professional attire while maintaining a stylish edge. It’s the most logical choice for a do-everything workhorse that plays to Threadripper’s strengths without spending too much of the budget on extras.

Three SafeSlots offer plenty of capacity for multiple graphics cards, and you still get a fourth slot linked to the CPU. Each of those has a dedicated connection, with no sharing between them, and the same is true for the PCIe pathways for storage. The primary M.2 slot shares a heatsink with the chipset to lower drive temperatures under load, and the secondary slot protrudes outward near the DIMM slots, where drives can be cooled by airflow from adjacent system and radiator fans. Factor in the U.2 port, and you’ve got a solid recipe for future SSD expansion or loading up from the start.

Although not equipped for elaborate liquid loops, the Prime X399-A still comes with two headers that simplify connecting pumps and all-in-one coolers. Along with those, its eight fan headers deliver enough smart cooling management for an entire build. The Prime is no stranger to overclocking, either. It has the same 5-Way Optimization auto-tuner as the ROG boards, as well as all the manual tweaking options that the vast majority of overclockers will ever need.

The processor’s full USB bounty is delivered through a multitude of ports in the rear cluster, and additional ports are accessible through onboard headers. There’s enough for a stack of devices, from peripherals to VR trackers, with room to add more down the road.

Two RGB headers prime the X399-A to illuminate up to four meters of lighting at optimal brightness. The lighting on the board itself is discreet, with a gentle glow emanating from below the chipset heatsink. Even with the lights turned off, the interplay of angular lines and bare metal makes the Prime stand out.

Sensible without being sedate, the Prime X399-A mixes business with pleasure at an affordable price. It’s slated to sell for $349.99 in the USA.