NVIDIA GeForce GTX 970M vs NVIDIA GeForce GTX 1080 SLI (Laptop) vs NVIDIA GeForce GTX 950M

NVIDIA GeForce GTX 970M

The NVIDIA GeForce GTX 970M is a high end DirectX 11.2 graphics card for laptops. The card is not yet officially announced and therefore the following information is based on rumors and leaks. The card based on the GM204 Maxwell chip, that is already available in the desktop GeForce GTX 970 and 980. Thanks to the improved efficiency, the GTX970M should be clearly faster than the previous GTX 870M and even the old GTX 880M.

NVIDIA GeForce GTX 1080 SLI (Laptop)

The Nvidia GeForce GTX 1080 SLI for laptops is a combination of two GTX 1080 graphics cards in SLI mode. Each card renders one frame at a time (AFR mode) but depends for most games on a good profile in the driver. Therefore, the performance can range from no gains over a single GTX 1080 to up to 90% faster performance. Sometimes, the combination may also suffer from micro-stuttering. The technical details of the card are identical to a single GTX 1080 (see for more information) and the power consumption is doubled. Therefore, the 1080 SLI combination is only found in huge clunky laptops.

NVIDIA GeForce GTX 950M

The NVIDIA GeForce GTX 950M is an (upper) mid-range, DirectX 11-compatible graphics card for laptops unveiled in March 2015. It is based on Nvidia's Maxwell architecture (GM107 chip) and manufactured in 28 nm. The GTX 950M offers 640 shader units clocked at 914 MHz (+ Boost) as well as fast GDDR5 memory (128 bit, 5000 MHz effective, 80 GB/s). Compared to the previous and technically very similar GTX 850M, the GTX 950M is clocked slightly higher. A detailed performance comparison of the GTX 950M with GDDR5 and DDR3 can be found here.

Some GTX 950M may be equipped with cheaper 900 - 1000 MHz DDR3 memory (1800 - 2000 MHz effective, 28.8 - 32 GB/s), which leads to a 10 - 20 percent lower performance despite the slightly higher core clock of 993 MHz.

Architecture

Compared to Kepler, Maxwell has been optimized in several details to increase power efficiency. Smaller Streaming Multiprocessors (SMM) with only 128 ALUs (Kepler: 192) and an optimized scheduler should lead to better utilization of the shaders. Nvidia promises that a Maxwell SMM with 128 ALUs can offer 90 percent of the performance of a Kepler SMX with 192 ALUs. GM107 features 5 SMMs and thus 640 shader cores, 40 TMUs and 16 ROPs (128-bit interface).

Another optimization is the massively enlarged L2 cache (GM107: 2 MB). The increased size can handle some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing the performance.

GM107 supports DirectX 12 with feature level 11_0 only.

Performance

Although the GTX 950M has the same memory bandwidth as the previous GTX 850M, its higher core clock leads to a slightly better performance. Overall, the 950M (GDDR5 version) is about 15 percent slower than the GTX 960M and just slightly behind the old GTX 860M.

Many games of 2014/2015 can be played fluently in FullHD resolution and high detail settings. However, very demanding games such as Assassin's Creed Unity will require lower resolutions and/or details.

Features

GM107 integrates the sixth generation of the PureVideo HD video engine (VP6), offering a better decoding performance for H.264 and MPEG-2 videos. Of course, VP6 supports all features of previous generations (4K support, PIP, video encoding via NVENC API). Unfortunately, HDMI 2.0 is still not supported.

Power Consumption

The power consumption of the GeForce GTX 950M should be similar to (or slightly above) the previous GTX 850M at about 50 watts. Therefore, the GPU is best suited for 15-inch laptops or larger. The 900M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.