Since our delid collaboration with Bitwit, we’ve been considering expanding VRM temperature testing on the ASUS Rampage VI Extreme to determine at what point the VRM needs direct cooling. This expanded into determining when it’s even reasonable to expect the stock heatsink to be capable of handling the 7980XE’s overclocked heat load: We are seeking to find at what point we tip into territory of being too power-hungry to reasonably operate without a fan directly over the heatsink.
This VRM thermal benchmark specifically looks at the ASUS Rampage VI Extreme motherboard, which uses one of the better X299 heatsinks for its IR3555 60A power stages. The IR3555 has an internal temperature sensor, which ASUS taps into for a safety throttle in EFI. As we understand it, the stock configuration sets a VRM throttle temperature of 120C – we believe this is internal temperature, though the diode could also be placed between the FETs, in which case the internal temperatures would be higher.
Tripping VRM overtemperature isn’t something we do too often, but it happened when working on Bitwit Kyle’s 7980XE. We’re working on a “collab” with Kyle, as the cool kids call it, and delidded an i9-7980XE for Kyle’s upcoming $10,000 PC build. The delidded CPU underwent myriad thermal and power tests, including similar testing to our previous i9-7980XE delid & 7900X “thermal issues” content pieces. We also benchmarked sealant vs. no sealant (silicone adhesive vs. nothing), as all of our previous tests have been conducted without resealing the delidded CPUs – we just rest the IHS atop the CPU, then clamp it under the socket. For Kyle’s CPU, we’re going to be shipping it across the States, so that means it needs to not leak liquid metal everywhere. Part of this is resolved with nail polish on the SMDs, but the sealant – supposing no major thermal detriment – should also help.
Tripping overtemperature is probably the most unexpected side of our journey on this project. We figured we’d publish some data to demonstrate an overtemperature trip, and what happens when the VRMs exceed safe thermals, but the CPU is technically still under TjMax.
Let’s start with the VRM stuff first: This is a complete sideshoot discussion. We might expand it into a separate content piece with more testing, but we wanted to talk through some of the basics first. This is primarily observational data, at this point, though it was logged.
Following-up our tear-down of the ASUS ROG Strix Vega 64 graphics card, Buildzoid of Actually Hardcore Overclocking now visits the PCB for an in-depth VRM & PCB analysis. The big question was whether ASUS could reasonably outdo AMD's reference design, which is shockingly good for a card with such a bad cooler. "Reasonably," in this sentence, means "within reasonable cost" -- there's not much price-to-performance headroom with Vega, so any custom cards will have to keep MSRP as low as possible while still iterating on the cooler.
The PCB & VRM analysis is below, but we're still on hold for performance testing. As of right now, we are waiting on ASUS to finalize its VBIOS for best compatibility with AMD's drivers. It seems that there is some more discussion between AIB partners and AMD for this generation, which is introducing a bit of latency on launches. For now, here's the PCB analysis -- timestamps are on the left-side of the video:
X299 VRM thermals have been a topic of interest in the lab lately, as we’ve continued to learn how to work with our new power testing tools and have fully revamped CPU thermal testing. The time will come eventually, but for now, we’ve worked with Buildzoid to run some calculations on VRM thermals with the Gigabyte X299 Gaming 9 motherboard. These numbers are based off of GN testing for this video, where we overclocked the CPU to 4.5~4.6GHz and checked for power consumption at the 8-pin headers (of which there are two).
The Gigabyte X299 Gaming 9 motherboard makes some interesting choices with its VRM components, ultimately balancing between “ridiculous overkill,” to quote Buildzoid, and merely adequacy. The board is one of the higher quality motherboards out there right now, and so is worth a watch on the PCB break-down:
Following our AMD Radeon Vega: Frontier Edition review and preceding tear-down, Buildzoid has now returned to analyze the AMD Vega: Frontier Edition PCB & VRM. This is a 12-phase design (doubled-up 6) that ultimately resembles something similar to a 290X Lightning, making it the hands-down best VRM we've seen on a reference card. Given that Vega: FE is $1000, that sort of makes sense -- but Buildzoid does pose some questions as to what's necessary and how much current is really going through the card.
When interviewing EVGA Extreme OC Engineer “Kingpin,” the term “dailies” came up – as in daily users, or “just gamers,” or generally people who don’t use LN2 to overclock their GPU. The GTX 1080 Ti Kingpin card is not a device built for “dailies,” but rather for extreme overclockers – people who are trying to break world records.
Cards like this – the Lightning would be included – do have a reason to exist. Criticism online sometimes calls such devices “pointless” for delivering the same overall out-of-box experience as nearly any other 1080 Ti, but those criticizing aren’t looking at it from the right perspective. A Kingpin, Lightning, or other XOC card is purchased to eliminate the need to perform hard mods to get a card up to speed. It’s usable out of the box as an XOC tool.
While we crank away at finalizing the review for the GTX 1080 Ti Gaming X, the Ryzen R5 CPUs, and some other products, we decided to run a PCB & VRM quality analysis of MSI’s card. The new GTX 1080 Ti Gaming X is another in a line of overbuilt VRMs, but interesting for a number of reasons (especially given the quality of this round’s reference VRM).
In our analysis of the PCB, we go over VRM design, overclocking potential, and power mods. The power mod section (toward the end of the video) discusses shunt shorting and how to trick the GPU into permitting a higher power throughput than natively allowed.
View Buildzoid’s analysis below:
GPU diode is a bad means for controlling fan RPM, at this point; it’s not an indicator of total board performance by any stretch of use. GPUs have become efficient enough that GPU-governed PWM for fans means lower RPMs, which means less noise – a good thing – but also worsened performance on the still-hot VRMs. We have been talking about this for a while now, most recently in our in-depth EVGA VRM analysis during the Great Thermal Pad Fracas of 2016. That analysis showed that the thermals were largely a non-issue, but not totally inexcusable. EVGA’s subsequent VBIOS update and thermal pad mods were sufficient to resolve any concern that lingered, though if you’re curious to learn more about that, it’s really worth just checking out the original post.
VBIOS updates and thermal pad mods were not EVGA’s only response to this. Internally, the company set forth to design a new PCB+cooler combination that would better detect high heat operation on non-GPU components, and would further protect said components with a 10A fuse.
In our testing today, we’ll be fully analyzing the efficacy of EVGA’s new “ICX” cooler design, to coexist with the long-standing ACX cooler. In our thermal analysis and review of the EVGA GTX 1080 FTW2 (~$630) & SC2 ICX cards (~$590), we’ll compare ACX vs. ICX coolers on the same card, MOSFET & VRAM temperatures with thermocouples and NTC thermistors, and individual cooler component performance. This includes analysis down to the impact the new backplate makes, among other tests.
Of note: There will be no FPS benchmarks for this review. All ICX cards with SC2 and FTW2 suffixes ship at the exact same base/boost clock-rates as their preceding SC & FTW counterparts. This means that FPS will only be governed by GPU Boost 3.0; that is to say, any FPS difference seen between an EVGA GTX 1080 FTW & EVGA GTX 1080 FTW2 will be entirely resultant of uncontrollable (in test) manufacturing differences at the GPU-level. Such differences will be within a percentage point or two, and are, again, not a result of the ICX cooler. Our efforts are therefore better spent on the only thing that matters with this redesign: Cooling performance and noise. Gaming performance remains the same, barring any thermal throttle scenarios – and those aren’t a concern here, as you’ll see.
EVGA's "Classified K|NGP|N" line has become the company's solution for extreme overclockers, similar to MSI's "Gaming" and "Lightning" card differentiations. The new GTX 780 Ti (which we broke-down over here) stands as the best video card for gaming right now, outpacing nVidia's more developer-focused TITAN and AMD's R9 290X.
EVGA has scrapped the reference design for the 780 Ti and opted for their own ACX-enabled active cooling solution. The 780 Ti natively runs at a TDP of 250W, but because overclocking increases wattage sent through the device, EVGA had to design with high power consumption in mind. This means improving the on-card VRM, cooling, and ability to accept higher wattage.
We've posted several articles that discuss what determines a "good motherboard for gaming," but until today, haven't had the chance to properly define what some of the more important board components do. Oscillating clock crystals, MOSFETs, chokes, the VRM, and other low-level motherboard components are defined in this post.
Judging from our forums, motherboards are one of the more nebulous components for hardware -- they all feel similar to each other, and from a specs sheet, it looks like there's not much separating one board from another. Part of this is because Intel and AMD have moved several controllers to the CPU, part is because the deeper differentiators between quality are often not listed on a product spec sheet.
After numerous questions from a large reddit thread, we've decided to start a new video/article series exploring the components on the components -- or what comprises each individual piece of hardware. Starting with the motherboard made sense.
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