NVIDIA GeForce GTX 970 vs NVIDIA GeForce GTX 950M vs NVIDIA GeForce GTX 980 (Laptop)

NVIDIA GeForce GTX 970

The Nvidia GeForce GTX 970 is a high end desktop graphics card based on the Maxwell architecture. As the faster GTX 980, the GTX 970 uses the GM204 chip, but with reduced shaders (2048 vs. 1664) and TMUs (128 vs 103). The graphics card is equipped with 4 GB GDDR5 (7 GHz effective). 3.5 GB of the 4 GB are connected with 224 Bit, the rest only with a 32 Bit interface. This can lead to some stuttering or reduced frame rates in games that use the full 4 GB. The similar named mobile GeForce GTX 970M is clearly slower as it features only 1280 shader cores.

Despite the unique memory configuration, the GTX 970 performs on average on par with the older GeForce GTX 780 Ti or a AMD Radeon R9 290X.

The GM204 supports CUDA, 3D Vision, PhysX, GeForce Experience, Surround, GameStream, GPU Boost 2.0, Adaptive Vertical Sync / G-SYNC, SLI, DSR, MFAA and Virtual Reality latency improvements.

The Maxwell architecture is very power efficient. While gaming, the card only uses as much power as the Radeon R9 285 which is more than 35% slower on average.

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.

NVIDIA GeForce GTX 980 (Laptop)

The NVIDIA GeForce GTX 980 for notebooks (not the GTX 980M, sometimes also referred to as GeForce GTX 990M) is an overclockable high-end graphics card for laptops. It is an desktop Geforce GTX 980 chip with the same specifications (2048 shaders, 1126 MHz base clock, 7 Gbps memory) based on selected GM204 chips (for lower power consumption).

The performance is also on a level with the desktop GTX 980. Due to the different cooling solutions, the long term performance may be slightly lower compared to a well cooled desktop, but Nvidia assures only small degrades in performance. Furthermore, the mobile GTX 980 supports overclocking out of the box and all laptop manufacturers plan to provide an easy to use tool to overclock the card on the fly.

The core features are also the same, so expect support for DirectX 12 (FL 12_1). There will be no support for the new H.265 video engine as found on the desktop GTX 950.

The power consumption of the card is a lot higher than other mobile graphics card like the GeForce GTX 980M (100 Watt TDP). According to Nvidia, the TDP of the reference design is still 165 Watt like in the desktop version. Including overclocking headroom, the power consumption may reach up to 200 Watt. Therefore, only big laptops with efficient cooling methods can house the GeForce GTX980 for laptops.