An AMD Threadripper X399 Motherboard Overview: A Quick Look at Seven Products
by Ian Cutress & Joe Shields on September 15, 2017 9:00 AM ESTASUS Prime X399-A
By contrast to the comparison between the two ASRock motherboards, ASUS has positioned their first two products further apart from each other. The Prime X399-A is aimed more at an entry into X399, although the ‘entry’ moniker might be misleading: these X399 motherboards are still being stacked to the hilt in functionality even for the ‘cheaper’ models.
The ASUS Prime X399-A follows previous Prime-A products in a white/grey styling, using a brushed metal and angled design across the heatsinks and PCB to show that this motherboard means business (or something like that). The key features of the Prime X399-A are going to be the extended power delivery heatsink arrangement, U.2 and M.2 storage support, ASUS’ upgrade to the Realtek audio and RGB support.
The baseline specifications for the majority of Threadripper boards are here: a full complement of 8 DIMMs for memory, a good set of PCIe slots for multiple-add in cards, SATA storage, Ethernet and USB 3.1 (10 Gbps) support. ASUS, by comparison to the ROG Zenith, has stripped this model down: there’s only one Ethernet port, no WiFi, only two M.2 slots, fewer USB ports (but still over a dozen), and fewer PCIe slots with reinforcement. Threadripper is a high-end product, so doing a complete strip down to the bare essentials negates the high-end aspect of the platform. Perhaps a surprise over the ROG is that the Prime-A has a two-digit LED debug, while the ROG does not.
Going through the board in detail, starting at the top, is the VRM arrangement. This is an eight-phase design, with a dual connected heatsink reaching around the memory slots to the rear panel, which has a small 40mm fan. On the other side of the socket, ASUS has placed both EPS connectors (one 8-pin, one 4-pin) on the top right of the board with the 24-pin ATX connector directly below. While this area is where ASUS normally places some of its more esoteric features, such as PCIe slot disabling switches, there is no need to here. Perhaps a little strange to most will be the placement of the M.2 slot underneath the 24-pin, which requires the M.2 be placed ‘standing-up’ and out of the board. ASUS provides an M.2 bracket to assist in rigidity here.
Below the M.2 is the onboard USB 3.1 (10 Gbps) header from the chipset, which is slowly becoming adopted as the onboard standard, with a small number of chassis manufacturers adopting it for adding front-panel ports. This is followed by one of the two USB 3.0 headers, a U.2 port, and six SATA ports.
The chipset heatsink, as shown by the RGB on the picture, houses a few LEDs to adjust the aesthetic through the onboard AURA SYNC software. The heatsink also houses an M.2 slot, like the ROG, and helps provide additional cooling for it if needed.
To the left of the chipset are the PCIe slots. In order to save some cost and provide a little bit of product differentiation, ASUS has decided to only equip three of the full-length slots with a reinforcement guard, although all four full-length slots are connected to the CPU. The full length slots are provided as x16/x8/x16/x8, and when users equip multiple graphics cards, the slots with the reinforcement guard are the best ones to use. The one without the guard is not worse in any way, however in a two or three card system, using x16/x16 or x16/x16/x8 is usually preferred to x16/x8 or x16/x8/x8 due to the slot spacing arrangement. There is an additional PCIe 2.0 x4 from the chipset present as well.
Below the PCIe slots are the onboard headers, including USB 3.0 headers, fan headers, RGB LED headers and a two-digit debug. This is also paired with a power button to test the motherboard when a hand is in the case but the case is not hooked up. To the right of this is the onboard audio, to which ASUS uses their customized version of the Realtek ALC1220. This is combined with upgraded filter caps, PCB separation, an EMI shield and a DTS software stack.
The rear panel, due to the positioning of the board, might look a little bare compared to the ROG. There is the BIOS reset button, a total of eight USB 3.0 ports, the gigabit Ethernet port provided via the Intel I211-AT controller, a USB 3.1 Type-A port and Type-C port from an ASMedia controller, and the audio jacks with SPDIF output.
| ASUS Prime X399-A | |
| Warranty Period | 3 Years |
| Product Page | Link |
| Price | $349.99 |
| Size | E-ATX |
| CPU Interface | TR4 |
| Chipset | AMD X399 |
| Memory Slots (DDR4) | Eight DDR4 Supporting 128GB Quad Channel Up to 3600 MHz (OC) |
| Network Connectivity | 1 x Intel I211-AT GbE |
| Wireless Network | N/A |
| Onboard Audio | SupremeFX S1220A |
| PCIe Slots for Graphics (from CPU) | 4 x PCIe 3.0 x16 Supports SLI/CF |
| PCIe Slots for Other (from Chipset) | 1 x PCIe 2.0 x4 (max) 1 x PCIe 2.0 x1 |
| Onboard SATA | 6x Supporting RAID 0/1/10 |
| Onboard SATA Express | None |
| Onboard M.2 | 2 x PCIe 3.0 x4 - NVMe or SATA |
| Onboard U.2 | 1 x |
| USB 3.1 | 1 x Type-A Port 1 x Type-C Port |
| USB 3.0 | 8 x Rear Panel Ports 2 x Headers |
| USB 2.0 | 2 x Headers |
| Power Connectors | 1 x 24-pin EATX 1 x 8-pin ATX 12V 1 x 4-pin ATX 12V |
| Fan Headers | 1 x M.2 1 x CPU 1 x CPU OPT 3 x Chassis 1 x AIO_PUMP 1 x 5-pin EXT_FAN |
| IO Panel | 1 x Intel NIC 1 x USB 3.1 Type-A 1 x USB 3.1 Type-C 8 x USB 3.0 Ports 1 x Optical S/PDIF out 5 x Audio jack 1 x USB BIOS Flashback Button |
Facebook
Twitter
RSS
99 Comments
View All Comments
LordanSS - Saturday, September 16, 2017 - link
My money is on the latter.... =/vgray35@hotmail.com - Friday, September 15, 2017 - link
With CPU power approaching 150 Amps, all these MBs are brain dead right out the gate, for using 50y old 8+ phase Buck converter topology, where VRMs with multiple phases still have poor response settling times (not one cycle settling but 20 cycles), lowish efficiencies way below 98% needing substantial heat sinks; while being saddled with the vagaries of inductive energy storage which takes up a lot of space and cost much more. Instead they should be using hybrid-PWM switching eliminating hard switch of high currents, where fractional cycle resonance ensures zero current switching and almost no switching losses. Resonance frequency scaling of the inductor/capacitor eliminates the need for ferrite cores altogether, reducing both size and core losses.http://www.powerelectronics.com/power-management/s...
Rehashing the same old power technologies with only stepwise minuscule improvements at each iteration, is not going to bode well at all. These engineers need to join the rest of us in the 21st century, and stop rehashing inductive energy storage solutions in power supplies. These new power topologies have been available for 5y to 8y now. And further this will also reduce EMI noise.
vgray35@hotmail.com - Friday, September 15, 2017 - link
I might add eliminating the multi-phase Buck converters for a solution based on PWM-resonance switching (hybrid switching), fractional cycle resonance (one cycle settling responses), and resonance scaling of resonance components, will likely permit a X399 mITX board to be made; with all that PSU space recovered for other purposes. Who will take up the challenge? AMD, ASROCK? Or will Intel beat AMD in the rush to high current capability at 99% efficiency? Or one of the other competitors out there! A clarion call to action this is to once and for all retire the Buck converter!ddriver - Friday, September 15, 2017 - link
I doubt they will even make a micro atx board, much less itx...It will be a waste, gigantic socket will take up most of the space, there won't be enough room for all 4 memory channels, the CPUs generous amount of PCIE lanes will be utterly wasted.
vgray35@hotmail.com - Friday, September 15, 2017 - link
Yes, and yet ASROCK put the X99 on a mITX board. However cutting heat from the VRM's by 60% to 70% or more should be done anyway, not to mention the graphics cards that draw even more power. Why settle for 95/96% efficiency (or worse in some cases) when one could get 98.5% to 99% efficiency. But then again you might be right concerning Thread Ripper, although I would still buy it with M2 slots on the back. The power delivery could be moved entirely to the back of the board without heat sinks with a total height of only 1.5mm (possibly at the center of socket itself on the back). The challenge of course is just as applicable to the graphics cards.ddriver - Saturday, September 16, 2017 - link
Hm, it seems that they launched some lga2066 boards recently, an asrock itx and an msi matx. TR4 however is still atx and up only...DanNeely - Friday, September 15, 2017 - link
I agree about how little sense it would make; but there have been a few LGA2011 mITX boards for people who only needed the higher core count. One of the two currently listed on Newegg uses SoDIMMs and riser boards around the CPU socket to make everything fit. Doing it for Threadripper would definitely be harder on account of the bigger socket; but I won't say never.Xajel - Saturday, September 16, 2017 - link
mITX is very hard even with riser boards & only 4x SO-DIMMsbut mATX on the other hand is very plausible... lets hope for a mATX version of the ASRock Pro Gaming with it's 10GbE ( and at least one of it's Intel's 1GbE ), at least 2 of it's M.2's and 6+ SATA ports... and please ASRock, add a front USB 3.1g2 header...
ddriver - Friday, September 15, 2017 - link
Amps, or amperes, is a unit of current, not a unit of power. Power is measured in watts."Rehashing the same old power technologies with only stepwise minuscule improvements at each iteration, is not going to bode well at all." - this is unfortunately a fact, and the de-fact motto of the industry.
ddriver - Friday, September 15, 2017 - link
I mean it is kinda naive to assume several years old switching circuits will find their way into the mainstream just because they are a few percent better.We've had gas turbine engines for decades, but they are still only used in tanks, helicopters or naval ships, while mainstream vehicles are still stuck with the internal combustion engine, which is easier to break, harder to maintain and a whooping 60% less efficient.