NVIDIA GeForce GTX 970M SLI vs NVIDIA GeForce GTX 1080 Mobile vs NVIDIA GeForce GTX 1060 (Desktop)

NVIDIA GeForce GTX 970M SLI

The NVIDIA GeForce GTX 970M SLI is a high-end DirectX 11-compatible graphics solution for laptops, consisting of two GeForce GTX 970M. Each card has a 28 nm GM204 GPU based on the Maxwell architecture, which is the same chip as found on the GTX 980M as well as several desktop cards. The clocks for the SLI-setup are usually identical to a single GTX 970M (924 MHz GPU, 1250 MHz memory).

With SLI, each card renders a single frame (AFR mode). Therefore, it may suffer from micro stuttering in low fps ranges of 30 fps. This happens because of different timespans between two frames (e.g., irregular delays between sequential frames).

Architecture

GM204 is based on Nvidia's Maxwell architecture, which replaces the previous Kepler generation. Among other changes, Nvidia have restructured the streaming multi processors (SMM) in order to increase workload and efficiency. Now each SMM contains only 128 shader units and 8 TMUs, which is noticeably less than an equivalent Kepler GPU. The GM204 features four GPCs, and each consists of four SMMs. But, in the GeForce GTX 970M, Nvidia have deactivated 6 of 16 SMMs. As a result, only 1280 shader ALUs and 80 TMUs are active. In addition, there are 48 ROPs in three clusters with 16 units each.

The memory interface has a bandwidth of 192-bits (3x 64 bit) for each of the two GPUs. Thanks to an improved compression algorithm, the connection to the GDDR5 memory should be significantly more efficient per MHz. Furthermore, the L1 (96 KB per SMM) and L2 caches (2 MB) have been significantly increased to lower the needed bandwidth. Compared to the mid-range GM107, the newer and larger GM204 has several additional features and changes. Aside from the improved polymorphic engine in the SSMs, it is also the first Nvidia chip to support DirectX 12 Feature Level 12_1.

Performance

With good driver support, SLI almost doubles the performance of a single card. The GTX 970M SLI outperforms the former GeForce GTX 880M SLI by about 10 percent and is the second fastest mobile graphics solution in late 2014. Only the significantly more expensive GTX 980M SLI offers even more 3D power and is about 30 percent faster. Nevertheless, the GTX 970M SLI is powerful enough to run even the most demanding games with highest details, AA/AF and resolutions exceeding FullHD.

Features

Most of the features are identical to the GeForce GTX 800M series. With the GTX 970M, there can be up to 4 active displays possible, but this will likely decrease due to Optimus. Displays can be connected with a maximum resolution of 3840 x 2160 pixels via DisplayPort 1.2 or HDMI 2.0 (no HDCP @ 4K). HD audio formats like Dolby True HD and DTS HD can be sent to a compatible receiver as bitstream. As with previous models, 3D Vision is not supported with Optimus.

The updated video processor VP6 supports the usual formats like H.264 and can also decode and encode H.265 with a resolution of up to 4K via the NVENC API. Several parallel streams, such as picture-in-picture in a Blu-Ray movie, are also possible.

Further features of the GTX 900M series, which are also partly supported by older cards, include Battery Boost (longer battery life during gaming), Shadowplay (recording of gaming videos up to 4K60p and 130 Mbit/s) and Gamestream (game streaming on Shield console). More information on these features are available here.

Power Consumption

The power consumption of each GeForce GTX 970M including its MXM board and memory should be similar to a GTX 870M with a specified TDP of 100 W, leading to a total TDP of about 200 W. Given the significantly higher performance, this can be considered a massive increase in performance-per-watt. Nevertheless, the SLI setup can only be used in very large and heavy gaming notebooks with powerful cooling systems. Under low load, dynamic clock rates help the GPUs to save energy.

NVIDIA GeForce GTX 1080 Mobile

The Nvidia GeForce GTX 1080 for laptops (formerly known as GTX 1080M) is the mobile counterpart of the desktop GeForce GTX 1080. It uses the same GP104 chip and was officially announced at 16. August. The performance should be around +-10% of a non overclocked desktop GTX 1080. The amount of shaders and other technical specifications should be identical.

The mobile GTX1080 is the successor to the GeForce GTX 980 for Laptops and offers a significantly higher performance at the same TDP.

For thin and light laptops Nvidia offer a Max-Q called version of the GTX 1080 with lower TDP and also significantly lower performance. Sadly this variant im sold with the same GTX 1080 name, making it hard to judge the performance.

The performance depends on the used thermal headroom, processor and game. In our benchmarks the mobile GTX 1080 was between 0 to 10 percent slower than the desktop GTX 1080. Therefore, the card also allows gaming in 4k for modern and demanding games of 2017. However, the performance depends on the cooling and TDP settings in each laptop. E.g. the MSI GT73VR (200 W TDP) is much faster than the 1080 in the Razer Blade Pro (<=150 W).

The GP104 chip is manufactured in 16nm FinFET process at TSMC and offers a range of new features. DisplayPort 1.4 (ready), HDMI 2.0b, HDR, Simultaneous Multi-Projection (SMP), improved H.265 video en- and decoders (for PlayReady 3.0) are only some of the improvements. See our detailed Pascal architecture article for more details.

Due to the high TDP, the mobile GTX 1080 is only suited for large laptops with high performance cooling solutions. The power consumption is ranging from 150 to 200 Watt (according to Nvidia, up to 220 W in the Asus G701VIK, G800, GX800). A low power version (Max-Q) is available beginning summer 2017 with a reduced TGP of 90 - 110 Watt (at a reduced performance).

NVIDIA GeForce GTX 1060 (Desktop)

The Nvidia GeForce GTX 1060 is a graphics card for desktops and high end laptops (upcoming, see our article for the mobile GTX 1060 for benchmarks and specs). It is based on the Pascal architecture and manufactured in 16 nm FinFET at TSMC. The GPU is be based on the smaller GP106 chip. In laptops it has the codename N17E-G1 and will be the successor to the old GTX 970M (predecessor). The laptop version should be launched in August 2016. The desktop version is already out.

The performance of the 6 GB version is on par with an older GeForce GTX 980 (desktop and laptop). Therefore, 1080p gaming at highest detail is currently the best use case for the card. A comprehensive review of the desktop GeForce GTX 1060 Founders Edition with 6 GB GDDR5 can be found here. Beware, the upcoming 3 GB desktop variant should feature 128 shader less but clocked slightly higher. Still the performance should be definately slower than the 6 GB version.