NVidia GeForce GTX 980 Ti SLI Benchmark & Review vs. GTX 980 SLI, Titan X

By Published June 04, 2015 at 5:00 pm

Test Methodology

We tested using our updated 2015 GPU test bench, detailed in the table below. Our thanks to supporting hardware vendors for supplying some of the test components. Thanks to Jon Peddie Research for GTX 970 & R9 280X support.

The latest GeForce press drivers were used during testing. AMD Catalyst 15.5 was used. Game settings were manually controlled for the DUT. Stock overclocks were left untouched for stock tests.

VRAM utilization was measured using in-game tools and then validated with MSI's Afterburner, a custom version of the Riva Tuner software. Parity checking was performed with GPU-Z. FPS measurements were taken using FRAPS and then analyzed in a spreadsheet.

Each game was tested for 30 seconds in an identical scenario on the two cards, then repeated for parity.

GN Test Bench 2015 Name Courtesy Of Cost
Video Card

GTX 980 Ti 6GB

CPU Intel i7-4790K CPU CyberPower
Memory 32GB 2133MHz HyperX Savage RAM Kingston Tech. $300
Motherboard Gigabyte Z97X Gaming G1 GamersNexus $285
Power Supply NZXT 1200W HALE90 V2 NZXT $300
SSD HyperX Predator PCI-e SSD Kingston Tech. TBD
Case Top Deck Tech Station GamersNexus $250
CPU Cooler Be Quiet! Dark Rock 3 Be Quiet! ~$60

Average FPS, 1% low, and 0.1% low times are measured. We do not measure maximum or minimum FPS results as we consider these numbers to be pure outliers. Instead, we take an average of the lowest 1% of results (1% low) to show real-world, noticeable dips; we then take an average of the lowest 0.1% of results for severe spikes.

We conducted a large suite of real-world tests, logging VRAM consumption in most of them for comparative analysis. The games and software tested include:

We already know GTA V and Far Cry 4 consume massive amounts of video memory, often in excess of the 2GB limits of some cards. GRID: Autosport and Metro: Last Light provide highly-optimized benchmarking titles to ensure stability on the bench. Shadow of Mordor, GTA V, & The Witcher 3 are new enough that they heavily eat VRAM. 3DMark offers a synthetic benchmark that is predictable in its results, something of great importance in benchmarking.

Games with greater asset sizes will spike during peak load times, resulting in the most noticeable dips in performance on the 2GB card as memory caches out. Our hypothesis going into testing was that although the two video cards may not show massive performance differences in average FPS, they would potentially show disparity in the 1% low and 0.1% low (effective minimum) framerates. These are the numbers that most directly reflect jarring user experiences during “lag spikes,” and are important to pay attention to when assessing overall fluidity of gameplay.

Overclocked tests were conducted using MSI Afterburner for application of settings. All devices were tested for performance, stability, and thermals prior to overclocking to ensure clean results. On the OC bench, devices were set to maximize their voltage ceiling with incremental gains applied to the core clock (GPU) frequency. MSI Kombustor, which loads the GPU 100%, was running in the background. Once stability was compromised -- either from crashing or artifacting -- we attempted to resolve the issue by fine-tuning other OC settings; if stability could not be achieved, we backed-down the core clock frequency until we were confident of stability. At this point, the device was placed on a burn-in test using Kombustor and 100% load for 30 minutes. If the settings survived this test without logged fault, we recorded the OC settings and logged them to our spreadsheet.

Final OCs were applied and tested on games for comparison.

Thermals were reported using Delta T over ambient throughout a 30-minute burn-in period using 3DMark FireStrike - Extreme, which renders graphics at 1440p resolution. This test loads the VRAM heavily, something Kombustor skips, and keeps the GPU under high load that is comparable to gaming demands. Temperatures were logged using MSI Afterburner.

3DMark Firestrike Extreme – GTX 980 Ti SLI vs. GTX 980 SLI

3DMark's Firestrike benchmark provides a baseline for analysis, but is a synthetic tool that simulates real-world use cases. Because Firestrike is synthetic, we sometimes see greater differences between devices than are present in gaming scenarios. Still, it's worth running the test as a means to see a clean ranking of product performance on the benchmark.

We used Firestrike Extreme, which renders graphics at 1440p instead of the 1080p of the base version.



GTA V Benchmark – GTX 980 Ti SLI vs. 980 SLI, Titan X

GTA V, although optimized in many regards, doesn't do so well on SLI configurations with advanced settings. Despite boasting the highest average FPS, the SLI GTX 980 Ti cards suffer from profoundly low 0.1% FPS (99.9 percentile frames); these are the 'drops' that users will visually see as 'stutter' when gaming, and create a jarring and unpleasant experience. Note that these were the worst when using 'advanced settings' options (as we do at 1080p for alternate load testing), and that disabling advanced graphics options (as shown in the 4K chart) produce more reasonable lows.



As for performance, the 980 Ti in SLI outranks the 980 in SLI, understandably, but only by ~8 FPS average. This 13% boost costs $300 more than the new GTX 980 price ($500, though that is still propagating), making for a rough value argument.

The Witcher 3 Benchmark – GTX 980 Ti SLI vs. 980 SLI, Titan X, 780 Ti

We wrote about the Witcher 3's performance in our day-1 benchmark, remarking about the game's poor optimization and disappointing performance. In our updated graphics optimization guide for The Witcher 3, we found that the game's 1.03 and 1.04 patches significantly bolstered performance, making for a more playable experience.



980 Ti cards in SLI offer another ~19~20% performance gain over SLI GTX 980s, a more sizable difference favoring the Ti cards. Part of this is likely due to driver optimization for the Witcher 3 made by nVidia.

Metro: Last Light – GTX 980 Ti SLI 4K & 1440p Benchmark

Metro: Last Light shows a larger performance disparity at 4K than the previous titles – a ~24% gain – but present almost no difference at 1440p (within margin of error). We're unsure of why this is happening or where the bottleneck is, though it's likely a driver or software side issue. The 4790K could also be choking with such powerful GPU throughput.

980-ti-sli-bench-mll4k 980-ti-sli-bench-mll1440

GRID: Autosport – GTX 980 Ti SLI 4K

GRID is another such title. As with Metro at 1440p, it appears GRID: Autosport is choking elsewhere in the pipe, as the SLI performance is effectively identical and within reach of the Titan X performance. In our 980 Ti review, we made a note that GRID: Autosport was the only title where the TiX drastically outperformed the GTX 980 Ti.


Shadow of Mordor – GTX 980 Ti SLI 4K & 1440p

Shadow of Mordor produces a 21.6% performance gain at 4K for the 980 Ti in SLI over the GTX 980. For point of comparison, the lone GTX 980 Ti performs 27% better than the lone GTX 980; the gap thins with SLI, but is still noteworthy. Shadow of Mordor is actually playable at 4K with SLI 980 Ti cards using Ultra settings.



Far Cry 4 – GTX 980 Ti SLI Benchmark

Far Cry 4 produces a ~16.7% performance delta over the GTX 980 SLI when using the 980 Ti cards in SLI. The gain against single GPUs is massive – nearly two-fold over the TiX – and produces playable 4K framerates. For the first time in my history testing Far Cry 4, I saw fluidity of frame output and playability without awkward choppiness.



Conclusion: Value is Tough, but Performance Excels

For the most part – aside from a few games that appear to choke in the pipeline when running SLI – the 980 Ti SLI configuration outputs exceptional framerates. Unfortunately, it's tough to argue 15 to 20% performance gains over the GTX 980 for an extra $300; granted, the framebuffer is larger on the Ti – 6GB vs. 4GB – and that could be advantageous in the near future.

Throwing the 980 Ti into SLI only offers value in the games where a more reasonable framerate advantage is shown, and is almost entirely relegated to higher resolution gaming. At 1080, which is largely unshown here, the framerates are already so absurdly high even with a single GPU that it just isn't worth SLI 980 Ti cards. At least, not unless you're trying for 1080p with 120FPS output, in which case it's arguable that the GTX 980s in SLI would be worth consideration.

At 1440p and 4K, there's an argument to be made in favor of the GTX 980 Ti SLI configuration for Mordor and The Witcher 3, which see >~20% performance gains for the two cards together.

Still, at $1300 for two, that's a tough sell. The one thing that is certain is the questionable nature of the Titan X's value right now; the $1000 card (currently $1100) is immediately outclassed by both the 980 SLI configuration (at $1000) and the 980 Ti configuration (a 30% price hike over MSRP). The GTX 980 Ti single solution, at $650 MSRP, performs effectively identically to the TiX sans GRID performance, further torpedoing the TiX for most use cases. Unless someone's planning a tri- or quad-SLI configuration with Titan Xs, at which point value is sort of a moot point, it's difficult to justify the purchase when nVidia's neighboring solutions perform so well.

We're hoping to try AMD's new GPUs in the near future and will revisit this topic at that time.

- Steve “Lelldorianx” Burke.

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Last modified on June 05, 2015 at 5:00 pm
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.

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