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 |
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vgray35@hotmail.com - Saturday, September 16, 2017 - link
A few % better - you are looking at it wrong. Platinum PSU units with peak 94% efficiency means 6% heat dissipated. Now at 99% efficiency that is 1% dissipated as heat. That means a 5/6th reduction in heat or 83% less heat which is not just a few percent better. Further the new topology yields a >70% cost reduction which is also not insignificant. Gas turbines are also too noisy by the way, which is the main reason these are not considered (expensive when they go wrong too), and thus not a good comparison versus improvements being discussed here. Are you saying the linked article on PWM-resonance and resonance scaling topology is not worthwhile, or the problems with Buck converter inductors is not a severely limited and highly noisy power solution? Perhaps Power Electronics engineering is not your field of interest at all!Manch - Monday, September 18, 2017 - link
ICE is not 60% less efficient than a gas turbine. A gas turbine doesn't scale downward well. One of similar power would actually less efficient as an equivalent rated ICE. Gas turbines are impractical for vehicles.One benefit of a turbine would be no tailgating. The intake would suck in and crap out small critters all over your windshield.
vgray35@hotmail.com - Friday, September 15, 2017 - link
Yes I appreciate that - we draw power (Watts) at the rate of Joules of energy per second, Notice I said "we draw power", but that is also directly reflected proportionally as current in Amps (or a rate of Coulombs per sec), There was not a direct inference that power is measured in Amps, but only (a) "We are drawing a measure of power", and (b) this is approaching proportionally a resultant 150A. Yes I probably could have said better, but in wise did I say power is measured in AMPS.vgray35@hotmail.com - Friday, September 15, 2017 - link
I do not believe a defacto motto of the industry is "we are wasting 5% in heat, so let us not bother with wasting only 1%). Clearly you did not read the link to the Power Electronics article (I surmise), as then you would have realized the solution offers a huge reduction in cost as well as heat. The cost factor is something everybody is interesting in, even the industry at large, in my humble opinion.ddriver - Friday, September 15, 2017 - link
Huge? Like what? 6-7% better? Maybe 8-9%?What I meant is the solution you linked to is like 99% efficient, a good buck converter is what? Like 90-92%?
That's nowhere near the difference between an internal combustion engine and a gas turbine, the latter being more than twice more efficient. And still no adoption, even thou the solution is not really all that complex, and decades old. They still only use gas turbines in the most demanding applications, which is pretty much the same as with the converters from that article, which that dude developed for NASA's most demanding applications. I am pretty sure computers in NASA run on buck converters too, and they will use his designs only for the stuff they launch into space.
You probably don't realize how immense of an impact it would have if all cars on the planet become more than twice as efficient, burning more than twice as little fuel, outputting less than half the harmful emissions, traveling twice as far on a single fill. It would completely dwarf the benefits of boosting computer power converters from 90 to 99% :)
I am not saying it is not cool, I am just saying there have been a lot more beneficial a lot more high priority solutions that haven't been adopted yet for a lot longer, so you should not be surprised that the entire industry hasn't switched to a new power converter design overnight. They will do as they will always do, they will milk the cow until it dies, and then make it into jerky, and only then will then go for the new and better thing.
vgray35@hotmail.com - Saturday, September 16, 2017 - link
As noted earlier, 92% which is 8% heat versus 99% which is 1% heat means a 7/8th reduction in heat or 87% reduction. Thinking this is only a 7% improvement differential is incorrect - it is in this example an 87% improvement. That is not small potatoes. When this is coupled with a corresponding large cost reduction, then it becomes apparent the chip manufacturers would rather make more money using the older technology. Maybe the PSU engineers are just plain lazy or are not following the advances in their field as they are snowed under with work.Let's keep the discussion focused on power supplies.vgray35@hotmail.com - Saturday, September 16, 2017 - link
The 600W @ 12V fed to the motherboard with ~8% losses is ~50W heat in the VRMs (driving 180W CPU, 320W GPU, leaving 100W for other parts), The ATX power supply is 90% efficient or less with 60W heat also in the same case. The GPU power supply also is another 25W waste power supply heat, for a total of 135W of waste heat (as opposed to the useful heat generated within the various components themselves, which is heat generated from useful work being done). It is tough to manage this 660W in the case, but over 135W of it (>21% low ball estimate) is waste heat from just power supplies alone (ATX PSU, VRMs, GPU supply), of which over 80% or 110W could be eliminated by abandoning the Buck converter topology. This of course is a simplistic view, as there are other components too that are ignored here, for brevity's sake. I suspect >25% of heat comes from power supplies alone which can be dramatically curtailed. It's a 3 ringed circus: ATX PSU steals 10% for itself, motherboard steals another 8% for itself and GPU steals a further 8% for itself. We have no control over the power drawn from the mega chips themselves, but we do have control over the power supplies that drive them, and manufacturers could be doing a lot better here. And this is by no means a monster power hungry system with only one high-end graphics card. A >85% reduction in power supply waste heat can be realized if the Buck converter is abandoned, and that applies to resonant LLC power supplies also. The motherboard manufacturers and ATX PSU manufacturers need to take this aspect much more seriously.http://www.powerelectronics.com/power-management/s...
AMD's Thread Ripper X399 and Intel's X299 platforms should have been their first attempt at abandoning the Buck, half-bridge, and resonant LLC topologies. They failed us in that regard. We need this fiasco to come to an end by using hybrid PWM-resonant switching and resonance scaling, which eliminates the ferrite cored inductors altogether, and replaces them with just copper traces on the PCB. This is not rocket science.
Oxford Guy - Saturday, September 16, 2017 - link
Motherboard makers seem pretty much incompetent. They can't even be bothered to issue BIOS updates to fix serious bugs.ddriver - Sunday, September 17, 2017 - link
Yeah, but then again, an overclocked TR is like 200W, even an entry level car is like 200 KILOWATTS. So percentages are not really that much indicative.The facts remain. A TR mobo with a better power regulator circuit will save like 10 watts of power, a car with a gas turbine engine will save like 100 KW of power.
That's 10 000 times larger saving measured on absolute scales. What's more important in your opinion? Saving a watt, or saving 10 000 watts? Naturally, I'd rather have both. The goal here is to illustrate how low of a priority it is to improve mobo power delivery compared to some other, longer standing improvement opportunities that have been ignored.
Icehawk - Sunday, September 17, 2017 - link
They tried turbine cars, they are terrible due to the way they deliver power. Several successful drag cars have used them as in that application the power delivery works well. Same reason we aren't going to be driving rocket cars.