It’s been a months-long journey of GTX 800, then GTX 900 rumors, broken embargoes, questions, and anticipation. The GTX 750 Ti saw the debut of NVidia’s Maxwell architecture almost 7 months ago, making for one of the first times the company has ever unveiled a low-end product before its architecture flagship. Then things went silent. Time passed, and as mobile 800-series GPUs began shipping, we still hadn’t heard about what would eventually become the GTX 900 series.
Then a box showed up.
“The World’s Most Advanced GPU” was written on the hefty black and green box, a few phone calls were made, and we knew it was time.
Maxwell sees significant architectural changes over its preceding Kepler and Fermi family members and will inevitably lead into Pascal, detailed here. You’ll see a lot of new buzzwords around the web today, the embargo now lifted, and we’ll go into detail on what each of these technologies means for the gaming audience. Among others, some key advancements include: Multi-Frame Sampled Anti-Aliasing (MFAA), Dynamic Super Resolution (DSR), VXGI (Voxel Global Illumination), third generation delta color compression, and VR Direct.
Today we're reviewing nVidia's GTX 980 and Maxwell architecture, benchmarking for gaming performance / FPS, and looking at the TDP and power features.
A quick note: Although this review was written prior to today, we will be at nVidia’s Santa Monica-based Game24 unveil event on Thursday, 9/18 from 6PM through midnight. Embargo lifted at 7:30PM PST during the event, so there may be additional event-based information published following this review. Subscribe to our Twitter, Facebook, YouTube, and home pages for all of that.
NVIDIA GeForce GTX 980 Benchmark & Specs Explanation Video
NVIDIA GeForce GTX 980 & 970 Video Card Specs
GTX 980 |
GTX 970 | GTX 780 Ti | |
GPU | GM204 | GM204 | GK-110 |
Fab Process | 28nm | 28nm | 28nm |
Texture Filter Rate (Bilinear) |
144.1GT/s | 109.2GT/s | 210GT/s |
TjMax | 95C | 95C | 95C |
Transistor Count | 5.2B | 5.2B | 7.1B |
ROPs | 64 | 64 | 48 |
TMUs | 128 | 104 | 240 |
CUDA Cores | 2048 | 1664 | 2880 |
BCLK | 1126MHz | 1050MHz | 875MHz |
Boost CLK | 1216MHz | 1178MHz | 928MHz |
Single Precision | 5TFLOPs | 4TFLOPs | 5TFLOPs |
Mem Config | 4GB / 256-bit | 4GB / 256-bit | 3GB / 384-bit |
Mem Bandwidth | 224GB/s | 224GB/s | 336GB/s |
Mem Speed | 7Gbps (9Gbps effective - read below) |
7Gbps (9Gbps effective) |
7Gbps |
Power | 2x6-pin | 2x6-pin | 1x6-pin 1x8-pin |
TDP | 165W | 145W | 250W |
Output | DL-DVI HDMI 2.0 3xDisplayPort 1.2 |
DL-DVI HDMI 2.0 3xDisplayPort 1.2 |
1xDVI-D 1xDVI-I 1xDisplayPort 1xHDMI |
MSRP | $550 | $330 | $600 |
The GTX 980 sports a new GPU – one that nVidia boasts is “easily the most advanced GPU ever made” – in the form of the GM204 semiconductor. During our meetings with various nVidia engineers and product managers, we learned that the GTX 980’s development saw continued focus on mitigating temperatures to allow for greater thermal headroom, aiding in the performance improvement. This is made clear by the 980’s somewhat impressive 165W TDP and the 970’s 145W TDP; for perspective, the previous-generation GTX 780 Ti sits at around 250W TDP, demanding 1 x 6-pin + 1 x 8-pin power connectors from the PSU.
The GTX 970’s TDP in particular is worthy of note: A single 6-pin power cable can support up to 150W of power given a reasonably-classed PSU, and although nVidia is shipping its reference 970 with two 6-pin connectors for safety in overclocking, there is single-header potential. 5W isn’t enough headroom for overclocking, though if a board partner wanted to build a lower power GTX 970 for more discreet HTPC / living room applications (with limited or no OC support), the TDP would theoretically allow for a single 6-pin header.
Because the watt draw directly impacts thermals in a GPU (though there are many other factors – like the cooling interface, DRAM, and VRM), we can expect more horsepower at a lower temperature and power bill. The GTX 980 and accompanying GM204 chip have about 2x the performance per Watt over Kepler. A 165W TDP on a flagship GPU is undoubtedly nVidia's way of kicking AMD where it hurts most.
The GTX 980’s major advancements have been in core performance (each core is approximately 40% more powerful than the CUDA cores used in Kepler devices), TDP, and underlying technology to improve gaming visuals. Note that although the GTX 980 and its accompanying GM204 chip may host fewer cores, they can still output better performance core-for-core in tuned gaming and high-end CUDA environments.
NVIDIA GeForce GTX 980 – Changes to Thermal Design and TDP
We’ve seen SLI creep ahead in marketing focus with each driver update and conference call for about a year now. NVidia wants SLI to grow in adoption among gamers and has been making sweeping driver performance tweaks to enable this, though there have always been concerns about multi-GPU thermals in adjacent configurations.
When in tri-SLI (cards forced adjacent) or dual adjacent SLI using cards equipped with backplates, we’ve seen significantly increased temperatures as a result of the backplate cutting into the airflow channel for the top and middle GPUs. This results in an undesirable thermal differential between the two devices, with the slot-1 device running notably hotter. NVidia has historically avoided the usage of a backplate due to these concerns, but that’s changing with the GTX 980.
The GTX 980 ships stock with a full-coverage backplate to improve PCB strength (reduce flexing) and the overall appearance of the card. To resolve thermal concerns in multi-GPU configurations, the backplate is slotted toward the rear-top of the device (the side opposing the top of the fan); users building with adjacent video cards can use a standard screwdriver to remove the small slotted portion, leaving the majority of the backplate in-tact while addressing heat concerns for the cornered card. This opens the airflow channel enough to produce what nVidia qualifies as good cooling performance.
We’ll test the efficacy of the backplate design as soon as we’re able to obtain a second GTX 980 for testing.
Continue to Page 2 for information on Maxwell's new technologies, including advanced color compression, memory architecture, 4K resolution scaling, and more.