NVIDIA GeForce GTX 980 Performance Review
The launch of the GeForce GTX 980 is supposed to provide gamers with a high end graphics card but, looking past its obvious performance features, the underlying Maxwell architecture represents a significant shift in GPU engineering philosophies. By approaching GPU design in a way that mirrors NASA’s “faster, better, cheaper” approach from the mid-90’s, NVIDIA is looking to offer something unique, forward-thinking and highly efficient without offering up performance like a sacrificial lamb. Considering what was achieved with Kepler and its various iterations, what we’re seeing today is nothing more than the tip of the iceberg.
NVIDIA’s Maxwell architecture was actually heralded by a seemingly nondescript pipe-cleaning part, the GTX 750 Ti. Its GM107 core allowed for impressive performance per watt output and set the stage perfectly for today’s follow-on launch of the GTX 980 and GTX 970. Many of GM107’s design advances have been carried over en masse to the higher end GM204 core which powers these higher-end Maxwell parts.
Unlike in previous generations, necessity has dictated that efficiency improvements are based on a given core architecture rather than switching to a different manufacturing process. Whereas Kepler’s optimizations on the performance per watt front partially originated from the switch towards 28nm, Maxwell doesn’t rely on anything quite a obvious to achieve its goals. While it still uses the same highly refined 28nm manufacturing process of its predecessors, power consumption and heat production are both far, far lower. By optimizing at the architectural and draw command levels, NVIDIA can remain on a mature, less expensive manufacturing process while deftly avoiding the potential supply issues which are typically created when using a new process technology.
Many aspects of this launch will look like NVIDIA’s Kepler introduction from more than two years ago. Back then a so-called “mid-range” part was also launched first since the competition had absolutely nothing to respond with and the focus was upon squeezing the most performance out of an energy-efficient core. Not much has changed in the last two years since NVIDIA’s architectural goals are still firmly tied at the hip to minimizing TDP while offering class-leading performance across both the mobile and desktop spaces. Due to a number of factors, these aspects eluded AMD’s grasp with Hawaii which will likely allow Maxwell to surge ahead on a number of different fronts.
In many ways Maxwell arguably have further reaching implications within the notebook space than it does on the desktop. While desktop gamers aren’t typically constrained with worries over power consumption, mobile users want gaming on the go and up until now, achieving playable framerates while maintaining battery efficiency has been nearly impossible. Maxwell will change this equation and has already been launched within a version of NVIDIA’s GTX 860M which is specifically targeted towards the thin and light segment.
NVIDIA’s new GM204 core will be used on a pair of graphics cards: the aforementioned GTX 980 and GTX 970. With the GTX 980 being the spiritual successor to the GTX 780 Ti / GTX 780 and boasting an incredible 5 Teraflops of single precision throughput, one would expect it to have significantly better specifications. On paper at least, it doesn’t but it can still easily outperform the GTX 780 Ti in many instances. There are just 2048 CUDA cores but due to Maxwell’s broad scale efficiency improvements those cores a far better utilized and can provide up to 40% better performance on a per-unit basis. The Texture Unit count has also seen a significant reduction but the internal processing format results in drastic uplifts here as well.
One area where NVIDIA is putting additional hard resources is within the Render Output Units. Since the Maxwell core can theoretically process a much greater amount of data than the GTX 780 Ti ever could, additional raster pipelines were required. The inclusion of 64 ROPs should also benefit the overall performance of the GPU’s local memory buffer which has already received a shot of adrenalin.
Speaking of memory, don’t let those memory performance numbers in the chart above fool you. NVIDIA is doing some clever backroom compression and efficiency optimizations which allow that 7Gbps GDDR5 memory to achieve throughput that’s roughly equal to a speed of 9.3Gbps. In theory that results in an effective bandwidth of 298 GB/s which is still well short of the GTX 780 Ti’s 336 GB/s and the R9 290X’s 320 GB/s. However, there’s now 4GB on tap for improved high resolution framerate consistency.
Much of the GM204’s stated improvements stem from its ability to reach extremely high clock frequencies which are a direct result of the core’s incredibly low TDP overhead. Even though the GTX 980 can hit over 1200MHz on a regular basis and the GTX 970 isn’t far behind at 1085MHz, their TDPs are only are only 165W and 145W respectively. Yes you read that right: these new cards are, in a broad sense, nearly 100W more efficient than their predecessors. That leads to a much cooler-running, less power hungry system. We can almost hear the ITX crowd rejoicing now….
With all of those factors taken into account, there are several factors other than clock speeds which make the GTX 970 different. NVIDIA can cut out a trio of SMM’s (Maxwell’s version of the SMX module) which results in 1664 cores and 104 Texture Units. Meanwhile, it retains the same back end as its bigger sibling so the ROP partitions, cache structure and memory interface remain intact.
Much like NVIDIA’s launch of the GTX 680, the GTX 980 and GTX 970 will be highly disruptive cards for the entire graphics market. The GTX 980’s price of $549 undercuts the GTX 780 Ti by a massive $150 and even manages to be just a bit more expensive than AMD’s substantially lower performing R9 290X. As a matter of fact, it is so disruptive, NVIDIA is discontinuing their GTX 780 Ti and GTX 780 without announcing any price cuts. This is likely due to the fact that there are very few of these cards left in the channel. Meanwhile, the GTX 760 will fall to the lower $219 bracket
The GTX 970 on the other hand will land at exactly the same price as the GTX 770 and will push that card into EOL status as well. NVIDIA’s numbers have this card beating the higher priced R9 290 by a substantial margin so this one-two punch will likely have AMD looking long and hard at their pricing structure.
By introducing a card that replaces the GTX 780 Ti at a much lower price point, NVIDIA is once again showing that they can create an efficient next generation mid-tier core that can compete with the best being offered only a few hours ago. They seem to have done so without moving towards a different manufacturing process which makes these achievements all that much more impressive on paper. However, past the paper specifications and a seemingly awesome price point, we still have to find out how the GTX 980 fares in true comparative testing.
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