A few days ago, we ran our most successful, highest-watched livestream in the history of GN. The stream peaked at >5300 concurrent viewers for around 2.5 hours, during which time we attempted to outmatch the LinusTechTips 3DMark score submitted to the 3DMark Hall of Fame. This was a friendly media battle that we decided to bring to LTT after seeing their submission, which briefly knocked us out of the Top 10 for the Hall of Fame. As noted in this recap video, we're not skilled enough to compete with the likes of K|NGP|N, dancop, der8auer, or similar pro XOCers, but we can certainly compete with other media. We made a spectacle of the event and pushed our i9-7980XE, our RAM, and our GPU (a Titan V) as far as our components would allow under ambient cooling. Ambient, by the way, peaked at ~30C during the stream; after the stream ended and room ambient dropped ~10C to 20C, our scores improved to 8285 in Timespy Extreme. This pushed us into 4th place on the 3DMark official Hall of Fame, and 3rd place in the HW Bot rankings.
The overclocking stream saw guest visits from Buildzoid of Actually Hardcore Overclocking, who assisted in tuning our memory timings for the final couple of points. We think there's more room to push here, but we'd like to keep some in the tank for a retaliation from Linus and team.
Even when using supposed “safe” voltages as a maximum input limit for overclocking via BIOS, it’s possible that the motherboard is feeding a significantly different voltage to the CPU. We’ve demonstrated this before, like when we talked about the Ultra Gaming’s Vdroop issues. The opposite side of Vdroop would be overvoltage, of course, and is also quite common. Inputting a value of 1.3V SOC, for instance, could yield a socket-side voltage measurement of ~1.4V. This difference is significant enough that you may exit territory of being “reasonably usable” and enter “will definitely degrade the IMC over time.”
But software measurements won’t help much, in this regard. HWINFO is good, AIDA also does well, but both are relying on the CPU sensors to deliver that information. The pin/pad resistances alone can cause that number to underreport in software, whereas measuring the back of the socket with a digital multimeter (DMM) could tell a very different story.
As we await arrival of our APUs today, we’ve seen a few news stories reporting “4.56GHz” overclocks (or similarly high clocks) on AMD’s new Ryzen+Vega amalgamation. Seemingly, this significantly higher overclock is achievable merely by entering S3 (sleep) in Windows, and is even easily validated with higher benchmark scores.
In reality, we believe this is the Windows timer bugging out, which has existed on previous platforms and CPUs. The bug is easy to replicate because it only requires entering S3 state – another commonly problematic Windows setting, based on a previous life of lab testing – and waking from S3 causes artificially high clock reports.
The goal for today is to trick an nVidia GPU into drawing more power than its Boost 3.0 power budget will allow it. The theoretical result is that more power will provide greater clock stability; we won’t necessarily get better overclocks or bigger offsets, but should stabilize and flatline the frequency, which improves performance overall. Typically, Boost clock bounces around based on load and power budget or voltage. We have already eliminated the thermal checkpoint with our Hybrid mod, and must now help eliminate the power budget checkpoint.
This content piece is relatively agnostic toward nVidia devices. Although we are using an nVidia Titan V graphics card, priced at $3000, the same practice of shunt resistor shorting can be applied to a 1080 Ti, 1070, 1070 Ti, or other nVidia GPUs.
“Shunts” are in-line resistors that have a known input voltage, which ultimately comes from the PCIe connectors or PCIe slot. In this case, we care about the in-line shunt resistors for the PCIe cables. The GPU knows the voltage across the shunt (12V, as it’s in-line with the power connectors), and the GPU also knows the resistance from the shunt (5mohm). By measuring the voltage drop across the shunt, the GPU can figure out how much current is being pulled, and then adjust to match power limitations accordingly. The shunt itself is not a limiter or a “dam,” but a measuring stick used to determine how much current is being used to drive the card.
Continuing our holiday buyer’s guides, hardcore overclocker Buildzoid has joined us to analyze the best AMD motherboards currently on the market, looking at X370 and B350 for overclocking. The boards scale from $75 to $350 as we step through nearly every single AM4 motherboard out there, with clear guidance as to which boards are most suitable for different tasks. This was primarily done as a video, but the written section below will recap the highlights. Timestamps are also provided, if the video is preferred.
For this AMD motherboard buyer’s guide, we’re primarily highlighting boards in the $120 to $200 price range, but do talk about some of the budget Ryzen motherboards. VRM capabilities and heatsinks, BIOS menus, and memory overclocking compatibility all factor into our choices.
Buildzoid of Actually Hardcore Overclocking recently joined us to explain what Load-Line Calibration is, and how LLC can be a useful tool for overclocking. LLC can also be dangerous to the life of the CPU if used carelessly, or when using the Extreme LLC setting without knowing fully how it works.
For anyone working on CPU overclocking and facing challenges with voltage stability, or anyone asking about Vdroop, LLC is a good place to start. LLC settings tuning should help stabilize voltage and prevent blasting the CPU with deadly Vcore. Learn more below:
Our 7900X delidding benchmarks weren’t published by coincidence: Today, we’re expanding on our liquid metal vs. Intel TIM testing with the new Intel i9-7960X and i9-7980XE CPUs, the 16C and 18C Skylake-X parts, respectively. These CPUs are Intel’s highest multithreaded performers in this segment, and are priced alongside that status – the 7960X costs $1700, with the 7980XE at $2000.
Rather than focusing entirely on delidding and thermal benchmarks, we’ll also be including power testing and some production benchmarks (Blender, Premiere). This review of the Intel i9-7960X and i9-7980XE will primarily test thermals, power, delidded thermals, liquid metal thermals, rendering benchmarks, and some synthetics.
Recapping the previous test approach for delidding & liquid metal:
Today's video showed some of the process of delidding the i9-7900X -- again, following our Computex delid -- and learning how to use liquid metal. It's a first step, and one that we can learn from. The process has already been applied toward dozens of benchmarks, the charts for which are in the creation stage right now. We'll be working on the 7900X thermal and power content over the weekend, leading to a much greater content piece thereafter. It'll all be focused on thermals and power.
As for the 7900X, the delid was fairly straight forward: We used Der8auer's same Delid DieMate tool that we used at Computex, but now with updated hardware. A few notes on this: After the first delid, we learned that the "clamp" (pressing vertically) is meant to reseal and hold the IHS + substrate still. It is not needed for the actual delid process, so that's one of the newly learned aspects of this. The biggest point of education was the liquid metal application process, as LM gets everywhere and spreads sufficiently without anything close to the size of 'blob' you'd use for TIM.
While traveling, the major story that unfolded – and then folded – pertained to the alleged unlocking of Vega 56 shaders, permitting the cards to turn into a “Vega 58” or “Vega 57,” depending. This ultimately was due to a GPU-Z reporting bug, and users claiming increases in performance hadn’t normalized for the clock change or higher power budget. Still, the BIOS flash will modify the DPM tables to adjust for higher clocks and permit greater HBM2 voltage to the memory. Of these changes, the latter is the only real, relevant change – clocks can be manually increased on V56, and the core voltage remains the same after a flash. Powerplay tables can be used to bypass BIOS power limits on V56, though a flash to V64 BIOS permits higher power budget.
Even with all this, it’s still impossible (presently) to flash a modified, custom BIOS onto Vega. We tried this upon review of Vega 56, finding that the card was locked-down to prevent modding. This uses an on-die security coprocessor, relegating our efforts to powerplay tables. Those powerplay tables did ultimately prove successful, as we recently published.
Everyone talks game about how they don’t care about power consumption. We took that comment to the extreme, using a registry hack to give Vega 56 enough extra power to kill the card, if we wanted, and a Floe 360mm CLC to keep temperatures low enough that GPU diode reporting inaccuracies emerge. “I don’t care about power consumption, I just want performance” is now met with that – 100% more power and an overclock to 1742MHz core. We've got room to do 200% power, but things would start popping at that point. The Vega 56 Hybrid mod is our most modded version of the Hybrid series to date, and leverages powerplay table registry changes to provide that additional power headroom. This is an alternative to BIOS flashing, which is limited to signed drivers (like V64 on V56, though we had issues flashing V64L onto V56). Last we attempted it, a modified BIOS did not work. Powerplay tables do, though, and mean that we can modify power target to surpass V56’s artificial power limitation.
The limitation on power provisioned to the V56 core is, we believe, fully to prevent V56 from too easily outmatching V64 in performance. The card’s BIOS won’t allow greater than 300-308W down the PCIe cables natively, even though official BIOS versions for V64 cards can support 350~360W. The VRM itself easily sustains 360W, and we’ve tested it as handling 406W without a FET popping. 400W is probably pushing what’s reasonable, but to limit V56 to ~300W, when an additional 60W is fully within the capabilities of the VRM & GPU, is a means to cap V56 performance to a point of not competing with V64.
We fixed that.
AMD’s CU scaling has never been that impacting to performance – clock speed closes most gaps with AMD hardware. Even without the extra shaders of V64, we can outperform V64’s stock performance, and we’ll soon find out how we do versus V64’s overclocked performance. That’ll have to wait until after PAX, but it’s something we’re hoping to further study.
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