NVIDIA GeForce GTX 1080 Ti (Desktop) vs NVIDIA GeForce GTX 950M

NVIDIA GeForce GTX 1080 Ti (Desktop)

The Nvidia GeForce GTX 1080 Ti is the fastest desktop consumer graphics card (beginning 2017). It is based on the same GP107 chip as the Titan X but with slightly higher clock speeds and a different memory configuration. It offers one memory controller less (and 11 instead of 12 GB), but the GDDR5X memory is faster clocked (11 GHz) leading to a comparable memory bandwidth. Due to the higher boost clock, the 1080Ti should be around 5 % faster compared to the Pascal Titan X and about 35 % faster compared to the GTX 1080. The TDP is equal to the Titan X with 250 Watt. A new cooler of the Founders Edition should be more efficient and quieter.

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.