Steve Burke

Steve Burke

Steve started GamersNexus back when it was just a cool name, and now it's grown into an expansive website with an overwhelming amount of features. He recalls his first difficult decision with GN's direction: "I didn't know whether or not I wanted 'Gamers' to have a possessive apostrophe -- I mean, grammatically it should, but I didn't like it in the name. It was ugly. I also had people who were typing apostrophes into the address bar - sigh. It made sense to just leave it as 'Gamers.'"

First world problems, Steve. First world problems.

This feature benchmark dives into one of the top requests we received from our Patreon backers: Undervolt Vega: Frontier Edition and determine its peak power/performance configuration. The test roped us in immediately, yielding performance uplift largely across the board from preliminary settings tuning. As we dug deeper, once past all the anomalous software issues, we managed to improve Vega: FE Air’s power available to the core, reduce power consumption relative to this, and improve performance in non-trivial ways.

Although power target and core voltage are somewhat tied at the hip, both being tools for overclocking, they don’t govern one another. Power target offset dictates how much additional power budget we’re willing to provide the GPU core (from the power supply) in order to stabilize its clock. GPU Vcore governs the voltage supplied, and will generally range from 900 to 1250mv on Vega: FE cards.

Vega’s native DPM configuration runs its final three states at 1440MHz, 1528MHz, and 1600MHz for the P-states, with DPM7 at 1600MHz/1200mv. This configuration is unsustainable in stock settings, as the core is both power-starved and thermally throttled (we’ll show this in a moment). The thermal limiter on Vega: FE is ~85C, at which point the power and clock will fluctuate hard to try and maintain control of the core temperature. The result is (1) spikey frequencies and frametime latencies, worsening perceived performance, and (2) reduced overall performance as frequency struggles to maintain even 1528MHz (let alone the advertised 1600MHz). To resolve for the thermal issue, we can either configure a more intelligent fan curve than AMD’s stock configuration or create a Hybrid card; unfortunately, we’re still left with a new problem – a power limit.

The power limit can be resolved in large part by offsetting power target by +50%. Making this modification is easy and “fixes” the issue of clock-dropping, but introduces (1) new thermal issues – resolvable by configuring a higher fan RPM, of course, and (2) absurdly high power consumption for a non-linear scaling in performance. In order to truly get value out of this approach, undervolting seems the next appropriate measure. AMD’s native core voltage is far higher than necessary for the card to operate at its 1600MHz target, and so lowering voltage improves performance from the out-of-box config. This is for thermal and power reasons alike. We ultimately see significantly reduced power consumption, to the tune of ~90W in some cases, a more stable core clock and thereby higher performance, and lower temperature – and thereby controllable noise.

We can’t get all the way down to the inner workings of the pump on this one, unfortunately, as all of our source images for the Vega: Frontier Edition – Watercooled card are from a reader. The reader was kind enough to remove the shroud from their new WC version of Vega: FE so that we could get an understanding of the basics, leading us to the conclusion that AMD has built one of the most expensive pre-built liquid cooling solutions for a graphics card.

The video tear-down goes into detail on the images we received, but we’ll revisit most of it here. The card uses the same base PCB, same VRM, same GPU/HBM layout and positioning, and same everything as the air-cooled card. The difference is entirely in the cooling solution, where the Delta VRM fan goes away and is replaced with an additional reservoir (more on that in a moment), while the GPU/VRM cooling is handled by liquid plates and a pump. The die-case finstack atop the I/O is also now gone, and the baseplate is simplified to an aluminum plate with no protrusions.

Liquid-cooling the AMD Vega: Frontier Edition card has proven an educational experience for us, yielding new information about power leakage and solidifying beliefs of a power wall. We also learned that overclocking without thermal barriers (or thermal-induced power barriers) grants significant performance uplift in some scenarios, including gaming and production, though is done at the cost of ~33A from the PSU over 12V PSU power.

Our results for the AMD Vega: Frontier Edition liquid-cooling hybrid mod are in, and this review covers the overclocking scalability, power limits, thermal change, and more.

The Hybrid mod was detailed in build log form over in part 1 of the endeavor. This mod wasn’t as straight-forward as most, seeing as we didn’t have any 64x64mm brackets for securing the liquid cooler to the card. Drilling through an Intel mounting plate for an Asetek cooler, we were ultimately able to get an Asetek 570LC onto the card, which we later equipped with a Gentle Typhoon 120mm fan. VRM FET cooling was handled by aluminum finstacks secured by thermal adhesive, cooled with 1-2x Corsair ML120 fans. That said, this VRM cooling solution also wasn’t necessary – we could have operated with just the fans, and did at one point operate with just the heatsinks (and indirect airflow).

Before getting started: Our Vega FE Hybrid mod has just gone through its final data pass, and is now in video editing and writing. The content will arrive tomorrow!

That cleared away, as we know a lot of folks are excited for the mod's results, we're now focusing on the MSI GTX 1080 Ti Lightning card momentarily. This is a video card that we first covered at Computex 2017, where we detailed initial specifications, MOSFETs and power components, and the target use case of XOC or heavy overclocking. We didn't yet have information on the card internals, but our latest tear-down (embedded below) gives some insight on the card's design. There are some unique features on this card that should pose an interesting A/B test during thermal benchmarking.

This episode of Ask GN returns with our new format, frontloading the episode with some discussion topics before feeding into the user-submitted questions. As always, for consideration in next episode, please leave your comment on the YouTube playback page or in our Ask GN Discord channel for Patreon backers.

The video opens with another “gift” from NZXT, some new power draw testing, AMD Vega naming thoughts (and rushed launches with Intel & AMD), and then addresses user questions. We hop around from liquid metal to CPU and airflow topics, giving a good spread to this episode.

Watch below – timestamps below the embedded video:

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