The ASUS Strix cooler is fairly straight-forward: The baseplate covers only key areas, like the VRAM, with the right half of the cooler taking care of VRM components. The baseplate is secured by several screws on the top side of the PCB, rather than using screws only in the back half of the card like most vendors do. This means that removal of the shroud consists of unscrewing two back-side Phillips screws, the four retention screws for the heatsink, and then some force. The baseplate is secured by two screws in the expansion cover, four screws around the GPU (top of the PCB), and several longer screws also on the top-side.

ASUS’ cooler is clearly less intense in its utilization of aluminum and engineering than EVGA’s ICX solution, but that doesn’t instantly make it worse: the stuff that’s being cooled matters, clearly, as do default fan profiles (something EVGA’s been routinely aggressive with). ASUS has a different VRM design from EVGA’s same-priced FTW3, which we detailed electrically here, opting to use the voltage controller used on nVidia’s FE card and a doubled 5-phase VRM (using IR3555 60A power stages).

The cooler is fairly straight-forward: There’s an aluminum baseplate that’s simply flat and contacting VRAM, two finstacks over the GPU and VRM, and 6x6mm heatpipes running through the heatsinks. ASUS uses straight fins rather than the new L-shaped design that EVGA’s been touting. The only difference is that, theoretically, the L-shaped fins provide additional surface area for a wider contact patch to thermal pads, but still allow for airflow. A straight fin allows all the airflow, but has a more limited contact patch with the thermal pads. In our final ACX VRM analysis, we found that thermal pads contacting straight fins do actually help quite a bit more than no contact at all, but the L-shaped design does improve this. Whether or not it’s relevant, of course, is a different story. VRMs can take a lot of heat – easily 125C, in most cases – and don’t really need special attention. It’s not a bad thing and helps with efficiency, but also not necessary.

Anyway, the ASUS Strix version of the 1080 Ti is priced at $780, meaning it’s among the most expensive two GTX 1080 Ti cards we’ve reviewed. The other would be the EVGA GTX 1080 Ti FTW3 (review is located here), with the rest of the packing landing at $750 (or $700 for the FE model). Stock frequency isn’t really a relevant thing to talk about with these cards, seeing as they just boost to whatever the thermal + power limits allow, anyway, but ASUS is going with 1708MHz boost - OC mode or 1683MHz boost - gaming mode.

Pascal means that we’re inevitably restricted in stock and overclocking performance, as voltage is regulated to a maximum of ~1.093v (to protect longevity of the silicon), despite the VRMs being capable of well over that target. This means that video card purchases should hinge almost entirely on thermal and acoustics performance, seeing as gaming performance is going to be effectively the same on all reasonably built 1080 Ti cards. Overclocking isn’t much of a differentiator, either.

For that reason, we’re focusing almost exclusively on thermals and noise for this review. The rest just doesn’t matter, plainly, as gaming performance is identical to everything else (within reason). The only real difference is in FE-type cards, where a thermal limit is encountered prior to other limits. This is resolved by converting it in to a Hybrid or running higher fan speeds.

GPU Testing Methodology

For our benchmarks today, we’re using a fully rebuilt GPU test bench for 2017. This is our first full set of GPUs for the year, giving us an opportunity to move to an i7-7700K platform that’s clocked higher than our old GPU test bed. For all the excitement that comes with a new GPU test bench and a clean slate to work with, we also lose some information: Our old GPU tests are completely incomparable to these results due to a new set of numbers, completely new testing methodology, new game settings, and new games being tested with. DOOM, for instance, now has a new test methodology behind it. We’ve moved to Ultra graphics settings with 0xAA and async enabled, also dropping OpenGL entirely in favor of Vulkan + more Dx12 tests.

We’ve also automated a significant portion of our testing at this point, reducing manual workload in favor of greater focus on analytics.

Driver version 378.78 (press-ready drivers for 1080 Ti, provided by nVidia) was used for all nVidia devices. Version 17.10.1030-B8 was used for AMD (press drivers).

A separate bench is used for game performance and for thermal performance.

Thermal Test Bench

Our test methodology for the is largely parallel to our EVGA VRM final torture test that we published late last year. We use logging software to monitor the NTCs on EVGA’s ICX card, with our own calibrated thermocouples mounted to power components for non-ICX monitoring. Our thermocouples use an adhesive pad that is 1/100th of an inch thick, and does not interfere in any meaningful way with thermal transfer. The pad is a combination of polyimide and polymethylphenylsiloxane, and the thermocouple is a K-type hooked up to a logging meter. Calibration offsets are applied as necessary, with the exact same thermocouples used in the same spots for each test.

Torture testing used Kombustor's 'Furry Donut' testing, 3DMark, and a few games (to determine auto fan speeds under 'real' usage conditions, used later for noise level testing).

Our tests apply self-adhesive, 1/100th-inch thick (read: laser thin, does not cause "air gaps") K-type thermocouples directly to the rear-side of the PCB and to hotspot MOSFETs numbers 2 and 7 when counting from the bottom of the PCB. The thermocouples used are flat and are self-adhesive (from Omega), as recommended by thermal engineers in the industry -- including Bobby Kinstle of Corsair, whom we previously interviewed.

K-type thermocouples have a known range of approximately 2.2C. We calibrated our thermocouples by providing them an "ice bath," then providing them a boiling water bath. This provided us the information required to understand and adjust results appropriately.

Because we have concerns pertaining to thermal conductivity and impact of the thermocouple pad in its placement area, we selected the pads discussed above for uninterrupted performance of the cooler by the test equipment. Electrical conductivity is also a concern, as you don't want bare wire to cause an electrical short on the PCB. Fortunately, these thermocouples are not electrically conductive along the wire or placement pad, with the wire using a PTFE coating with a 30 AWG (~0.0100"⌀). The thermocouples are 914mm long and connect into our dual logging thermocouple readers, which then take second by second measurements of temperature. We also log ambient, and apply an ambient modifier where necessary to adjust test passes so that they are fair.

The response time of our thermocouples is 0.15s, with an accompanying resolution of 0.1C. The laminates arae fiberglass-reinforced polymer layers, with junction insulation comprised of polyimide and fiberglass. The thermocouples are rated for just under 200C, which is enough for any VRM testing (and if we go over that, something will probably blow, anyway).

To avoid EMI, we mostly guess-and-check placement of the thermocouples. EMI is caused by power plane PCBs and inductors. We were able to avoid electromagnetic interference by routing the thermocouple wiring right, toward the less populated half of the board, and then down. The cables exit the board near the PCI-e slot and avoid crossing inductors. This resulted in no observable/measurable EMI with regard to temperature readings.

We decided to deploy AIDA64 and GPU-Z to measure direct temperatures of the GPU and the CPU (becomes relevant during torture testing, when we dump the CPU radiator's heat straight into the VRM fan). In addition to this, logging of fan speeds, VID, vCore, and other aspects of power management were logged. We then use EVGA's custom Precision build to log the thermistor readings second by second, matched against and validated between our own thermocouples.

The primary test platform is detailed below:

Note also that we swap test benches for the GPU thermal testing, using instead our "red" bench with three case fans -- only one is connected (directed at CPU area) -- and an elevated standoff for the 120mm fat radiator cooler from Asetek (for the CPU) with Gentle Typhoon fan at max RPM. This is elevated out of airflow pathways for the GPU, and is irrelevant to testing -- but we're detailing it for our own notes in the future.

Game Bench 

BIOS settings include C-states completely disabled with the CPU locked to 4.5GHz at 1.32 vCore. Memory is at XMP1.

We communicated with both AMD and nVidia about the new titles on the bench, and gave each company the opportunity to ‘vote’ for a title they’d like to see us add. We figure this will help even out some of the game biases that exist. AMD doesn’t make a big showing today, but will soon. We are testing:

• Ghost Recon: Wildlands (built-in bench, Very High; recommended by nVidia)
• Sniper Elite 4 (High, Async, Dx12; recommended by AMD)
• For Honor (Extreme, manual bench as built-in is unrealistically abusive)
• Ashes of the Singularity (GPU-focused, High, Dx12)
• DOOM (Vulkan, Ultra, 0xAA, Async)

Synthetics:

• 3DMark FireStrike
• 3DMark FireStrike Extreme
• 3DMark FireStrike Ultra
• 3DMark TimeSpy

For measurement tools, we’re using PresentMon for Dx12/Vulkan titles and FRAPS for Dx11 titles. OnPresent is the preferred output for us, which is then fed through our own script to calculate 1% low and 0.1% low metrics (defined here).

Power testing is taken at the wall. One case fan is connected, both SSDs, and the system is otherwise left in the "Game Bench" configuration.

Continue to Page 2 for Thermals, Noise, & Conclusion.