This content marks the beginning of our in-depth VR testing efforts, part of an ongoing test pattern that hopes to determine distinct advantages and disadvantages on today’s hardware. VR hasn’t been a high-performance content topic for us, but we believe it’s an important one for this release of Kaby Lake & Ryzen CPUs: Both brands have boasted high VR performance, “VR Ready” tags, and other marketing that hasn’t been validated – mostly because it’s hard to do so. We’re leveraging a hardware capture rig to intercept frames to the headsets, FCAT VR, and a suite of five games across the Oculus Rift & HTC Vive to benchmark the R7 1700 vs. i7-7700K. This testing includes benchmarks at stock and overclocked configurations, totaling four devices under test (DUT) across two headsets and five games. Although this is “just” 20 total tests (with multiple passes), the process takes significantly longer than testing our entire suite of GPUs. Executing 20 of these VR benchmarks, ignoring parity tests, takes several days. We could do the same count for a GPU suite and have it done in a day.
VR benchmarking is hard, as it turns out, and there are a number of imperfections in any existing test methodology for VR. We’ve got a good solution to testing that has proven reliable, but in no way do we claim that perfect. Fortunately, by combining hardware and software capture, we’re able to validate numbers for each test pass. Using multiple test passes over the past five months of working with FCAT VR, we’ve also been able to build-up a database that gives us a clear margin of error; to this end, we’ve added error bars to the bar graphs to help illustrate when results are within usual variance.
Benchmarking Mass Effect: Andromeda immediately revealed a few considerations for our finalized testing. Frametimes, for instance, were markedly lower on the first test pass. The game also prides itself in casting players into a variety of environs, including ship interiors, planet surfaces of varying geometric complexity (generally simpler), and space stations with high poly density. Given all these gameplay options, we prefaced our final benchmarking with an extensive study period to research the game’s performance in various areas, then determine which area best represented the whole experience.
Our Mass Effect: Andromeda benchmark starts with definitions of settings (like framebuffer format), then goes through research, then the final benchmarks at 4K, 1440p, and 1080p.
Not long ago, we opened discussion about AMD’s new OCAT tool, a software overhaul of PresentMon that we had beta tested for AMD pre-launch. In the interim, and for the past five or so months, we’ve also been silently testing a new version of FCAT that adds functionality for VR benchmarking. This benchmark suite tackles the significant challenges of intercepting VR performance data, further offering new means of analyzing warp misses and drop frames. Finally, after several months of testing, we can talk about the new FCAT VR hardware and software capture utilities.
This tool functions in two pieces: Software and hardware capture.
Thermal cameras have proliferated to a point that people are buying them for use as tech toys, made possible thanks to new prices nearer $200 than the multi-thousand thermal imaging cameras that have long been the norm. Using a thermal camera that connects to a mobile phone eliminates a lot of the cost for such a device, relying on the mobile device’s hardware for post-processing and image cleanup that make the cameras semi-useful. They’re not the most accurate and should never be trusted over a dedicated, proper thermal imaging device, but they’re accurate enough for spot-checking and rapid concepting of testing procedures.
Unfortunately, we’ve seen them used lately as hard data for thermal performance of PC hardware. For all kinds of reasons, this needs to be done with caution. We urged in our EVGA VRM coverage that thermal imaging was not perfect for the task, and later stuck thermal probes directly to the card for more accurate measurements. Even ignoring the factors of emission, transmission, and reflection (today’s topics), using thermal imaging to take temperature measurements of core component temperatures is methodologically flawed. Measuring the case temperature of a laptop or chassis tells us nothing more than that – the temperature of the surface materials, assuming an ideal black body with an emissivity close to 1.0. We’ll talk about that contingency momentarily.
But even so: Pointing a thermal imager at a perfectly black surface and measuring its temperature is telling us the temperature of the surface. Sure, that’s useful for a few things; in laptops, that could be determining if case temperature exceeds the skin temp specification of a particular manufacturer. This is good for validating whether a device might be safe to touch, or for proving that a device is too hot for actual on-lap use. We could also use this information as troubleshooting to help us determine where hotspots are under the hood, potentially useful in very specific cases.
That doesn’t, however, tell us the efficacy of the cooling solution within the computer. For that, we need software to measure the CPU core temperatures, the GPU diode, and potentially other components (PCH and HDD/SSD are less popular, but occasionally important). Further analysis would require direct thermocouple probes mounted to the SMDs of interest, like VRM components or VRAM. Neither of these two examples are equipped with internal sensors that software, and even the host GPU, is capable of reading.
Two EVGA GTX 1080 FTW cards have now been run through a few dozen hours of testing, each passing through real-world, synthetic, and torture testing. We've been following this story since its onset, initially validating preliminary thermal results with thermal imaging, but later stating that we wanted to follow-up with direct thermocouple probes to the MOSFETs and PCB. The goal with which we set forth was to create the end-all, be-all set of test data for VRM thermals. We have tested every reasonable scenario for these cards, including SLI, and have even intentionally attempted to incinerate the cards by running ridiculous use scenarios.
Thermocouples were attached directly to the back-side of the PCB (hotspot previously discovered), the opposing MOSFET (#2, from bottom-up), and MOSFET #7. The seventh and second MOSFETs are those which seem to be most commonly singed or scorched in user photos of allegedly failed EVGA 10-series ACX 3.0 cards, including the GTX 1060 and GTX 1070. Our direct probe contact to these MOSFETs will provide more finality to testing results, with significantly greater accuracy and understanding than can be achieved with a thermal imager pointed at the rear-side of the PCB. Even just testing with a backplate isn't really ideal with thermal cameras, as the emissivity of the metal begins to make for questionable results -- not to mention the fact that the plate visually obstructs the actual components. And, although we did mirror EVGA & Tom's DE's testing methodology when checking the impact of thermal pads on the cards, even this approach is not perfect (it does turn out that we were pretty damn accurate, though, but it's not perfect. More on that later.). The pads act as an insulator, again hiding the components and assisting in the spread of heat across a larger surface area. That's what they're designed to do, of course, but for a true reading, we needed today's tests.
Virtual reality has begun its charge to drive technological development for the immediate future. For better or worse, we've seen the backpacks, the new wireless tether agents, the "VR cases," the VR 5.25" panels -- it's all VR, all day. We still believe that, although the technology is ready, game development has a way to travel yet -- but now is the time to start thinking about how VR works.
NVIDIA's Tom Petersen, Director of Technical Marketing, recently joined GamersNexus to discuss the virtual reality pipeline and the VR equivalent to frametimes, stutters, and tearing. Petersen explained that a "warp miss" or "drop frame" (both unfinalized terminology) are responsible for an unpleasant experience in VR, but that the consequences are far worse for stutters given the biology involved in VR.
In the video below, we talk with Petersen about the VR pipeline and its equivalencies to a traditional game refresh pipeline. Excerpts and quotations are below.
We're working on finalizing our validation of the EVGA VRM concerns that arose recently, addressed by the company with the introduction of a new VBIOS and optional thermal pad solution. We tested each of these updates in our previous content piece, showing a marked improvement from the more aggressive fan speed curve.
Now, that stated, we still wanted to dig deeper. Our initial testing did apply one thermocouple to the VRM area of the video card, but we weren't satisfied with the application of that probe. It was enough to validate our imaging results, which were built around validating Tom's Hardware DE's results, but we needed to isolate a few variables to learn more about EVGA's VRM.
We toured Corsair's new offices about a year ago, where we briefly posted about some of the validation facilities and the then-new logo. Now, with the offices fully populated, we're revisiting to talk wind tunnels, thermal chambers, and test vehicles for CPU coolers and fans. Corsair Thermal Engineer Bobby Kinstle walks us through the test processes for determining on-box specs, explaining hundreds of thousands of dollars worth of validation equipment along the way.
This relates to some of our previous content, where we got time with a local thermal chamber to validate our own methodology. You might also be interested to learn about when and why we use delta values for cooler efficacy measurements, and why we sometimes go with straight diode temperatures (like thermal limits on GPUs).
Video here (posting remotely -- can't embed): https://www.youtube.com/watch?v=Mf1uI2-I05o
We're still on the road – but it's almost over. For now. Last “Ask GN” update, we were posting from the Orange County / LA area for some hardware vendor visits that we'd done. This episode, despite being filmed at the usual set, we're posting from the San Jose area. It worked out to be: LA > Home > LA (CitizenCon) > San Jose, all in a span of about 3 weeks.
But we're here for another day before returning to hardware reviews. For this episode, we discuss the question of using a FreeSync display with a higher-end nVidia card versus a lower performing AMD card, VRM blower fans and if they do anything, the 6700K vs. 6600K, and revisiting old GPUs. The last question is one that we've already begun working on.
“Ye-- ye cain't take pictures h-- here,” a Porky Pig-like voice meekly spoke up from behind the acrylic windshield of a golf cart that'd rolled up behind us, “y-ye cain't be takin' pictures! I'm bein' nice right now!”
Most folks in media production, YouTube or otherwise, have probably run into this. We do regularly. We wanted to shoot an Ask GN episode while in California, and decided to opt for one of the fountains in Fountain Valley as the backdrop. That's not allowed, apparently, because that's just how rare water is in the region – don't look at it the wrong way. It might evaporate. Or something.
But no big deal – we grab the bags and march off wordlessly, as always, because this sort of thing just happens that frequently while on the road.
Regardless, because Andrew was not imprisoned for sneaking a shot of the fountain into our video or taking two pretzel snacks on the plane, Ask GN 29 has now been published to the web. The questions from viewers and readers this week include a focus on “why reviewers re-use GPU benchmark results” (we don't – explained in the video), the scalers in monitors and what “handles stretching” for resolutions, pump lifespan and optimal voltage for AIOs, and theoretical impact from HBM on IGPs.
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