NVIDIA GTX 980 SLI Review

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Onscreen Frame Timing

Onscreen Frame Timing

When capturing output frames in real-time, there are a number of eccentricities which wouldn’t normally be picked up by FRAPS but are nonetheless important to take into account. For example, some graphics solutions can either partially display a frame or drop it altogether. While both situations may sound horrible, these so-called “runts” and dropped frames will be completely invisible to someone sitting in front of a monitor. However, since these are counted by its software as full frames, FRAPS tends to factor them into the equation nonetheless, potentially giving results that don’t reflect what’s actually being displayed.

With certain frame types being non-threatening to the overall gaming experience, we’re presented with a simple question: should the fine-grain details of these invisible runts and dropped frames be displayed outright or should we show a more realistic representation of what you’ll see on the screen? Since Hardware Canucks is striving to evaluate cards based upon and end-user experience rather than from a purely scientific standpoint, we decided on the latter of these two methods.

With this in mind, we’ve used the FCAT tools to add the timing of partially rendered frames to the latency of successive frames. Dropped frames meanwhile are ignored as their value is zero. This provides a more realistic snapshot of visible fluidity.

These first few frame timing tests really don't tell us anything we didn't already know about NVIDIA's attention to this key metric. For the most part the readouts are smooth with the lone exception being Call of Duty: Ghosts which showed some spikes as the game loaded assets.

 

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Onscreen Frame Times (pg.2)

Onscreen Frame Times (pg.2)

Rounding out the results is really more of the same but here the GTX 980 SLI does somewhat improve (on paper at least) over the GTX 780 SLI setup. However, although we are able to see an altogether smoother readout from the Maxwell-based card, the actual visible differences are absolutely nil since the difference between a 10ms delta and one that's 30ms is impossible to perceive with the naked eye.

 

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Acoustics & Power Consumption

Acoustical Testing

What you see below are the baseline idle dB(A) results attained for a relatively quiet open-case system (specs are in the Methodology section) sans GPU along with the attained results for each individual card in idle and load scenarios. The meter we use has been calibrated and is placed at seated ear-level exactly 12” away from the GPU’s fan. For the load scenarios, Hitman Absolution is used in order to generate a constant load on the GPU(s) over the course of 15 minutes.

The GTX 980 is a pretty quiet card by itself which did bode well for SLI testing. With that being said, having a pair of the reference cards in your system will net some noticeable noise if they’re running alongside quiet case fans. If you’re looking for something quieter, opt for one of the many non-reference designs.

Compared against the turbine-like, ear-blasting noise profile of AMD’s R9 290X two of the GTX 980’s are whisper quiet. The R9 295X2 does however beat them out by a slim margin in our test.

System Power Consumption

For this test we hooked up our power supply to a UPM power meter that will log the power consumption of the whole system twice every second. In order to stress the GPU as much as possible we used 15 minutes of Unigine Valley running on a loop while letting the card sit at a stable Windows desktop for 15 minutes to determine the peak idle power consumption.

Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.

The Maxwell architecture is ultra power efficient despite being built on an older 28nm manufacturing process and these results back that up. A pair of GTX 980’s are able to easily outperform two R9 290X’s while consuming over 150W less power. If that isn’t a testament to the amount of engineering backstopping these cards, we don’t know what is.

 

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Conclusion

Conclusion

This conclusion is going to follow some pretty straightforward lines, many of which were already established in our initial GTX 980 review. However, there are also some noteworthy developments on the pricing front that may just project some competing solutions back into the limelight.

Let’s start with the obvious points first. From a raw framerate perspective a GTX 980 SLI setup will net you the highest possible performance in the vast majority of applications. Granted, there are some outlier situations where this new architecture can’t quite outperform two GTX 780 Ti’s in SLI but when compared against a an ultra-expensive solution like the TITAN Z, it’s nearly impossible to make a case for spending $3000. With that being said, dual GTX 780 Ti users should sit tight for the time being since upgrading to Maxwell won’t result in a noticeable performance improvement, even at 4K. It is also great to see nearly linear scaling between one and two cards on drivers that have yet to mature.

Speaking of UHD resolutions, it may come as a surprise that the GTX 980’s 4GB framebuffer doesn’t project it further into the lead when pushing so many pixels. There were a few situations where the extra memory may have been utilized but by and large the gap between it and the GTX 780 Ti remained nearly identical regardless of the resolution being tested. Simply put, today’s games (or should we say “yesterday’s games” since there hasn’t been a meaningful AAA title released on the PC in some time?) just don’t require more than 3GB unless MSAA is turned up to insane levels. When that happens, the architecture itself becomes a bottleneck more often than not. 4GB does add a bit of future proofing though, particularly as the holiday season’s rush of new titles approaches.

From a frametime perspective, the GTX 980 SLI typically presents a buttery smooth experience which is no different from its predecessor. This was to be expected since NVIDIA has been at the forefront of frame pacing technology and testing. Again, we already knew all of this but it is nonetheless good to see vindication in a relatively immature driver stack and architecture.

One of the big surprises in this review was actually the R9 295X2 when gaming at 4K. It may not compete directly with the GTX 980 SLI in the framerate or power efficiency departments but with AMD’s latest price cuts it is some $100 less expensive. That’s not a huge difference but if you happen to have a compatible SFF chassis, it offers fitment options that two NVIDIA cards can’t hope to match alongside the ability to process an immense number of frames.

What do these strengths mean for the R9 290X Crossfire option? Absolutely nothing unfortunately. Even with its lower overall cost, it doesn’t have the 295X2’s novelty or compatibility factors and it still gets blasted by the GTX 980 in performance and power consumption. 4K adds some relief though and if you’re approaching UHD gaming from a slightly more budget-friendly standpoint, two R9 290X’s do provide a good amount of bang for your buck.

For those who need an insane amount of performance, a GTX 980 SLI setup is currently the only way to go. It even delivers some semblance of value when you consider a few weeks ago this amount of horsepower would have cost $400 more. While the dual R9 290X setup does give NVIDIA’s newcomer a run for its money at 4K and the R9 295X2 is a viable option for small form factor systems, Maxwell still has a distinct edge in available feature support (depending on how much value you put in the Mantle argument that is…) , efficiency and overall performance. Two of these cards will provide peace of mind for a long, long time given today’s gaming landscape.