Release date | September 2014 |
---|---|
Codename | GM20x |
Architecture | Maxwell |
Models | GeForce Series
|
Cards | |
Mid-range | GeForce GTX 950 GeForce GTX 960 |
High-end | GeForce GTX 970 GeForce GTX 980 |
Enthusiast | GeForce GTX 980 Ti GeForce GTX Titan X |
API support | |
Direct3D | Direct3D 12 (feature level 12_1) |
OpenCL | OpenCL 1.2 |
OpenGL | OpenGL 4.5 |
Vulkan |
Vulkan 1.0 SPIR-V |
History | |
Predecessor | GeForce 700 series |
Successor | GeForce 10 series |
The GeForce 900 Series is a family of graphics processing units developed by Nvidia, used in desktop and laptop PCs. It serves as the high-end introduction for the Maxwell architecture (GM-codenamed chips), named after the Scottish theoretical physicist James Clerk Maxwell.
The Maxwell microarchitecture, the successor to Kepler microarchitecture. Nvidia expected three major things from the Maxwell architecture: improved graphics capabilities, simplified programming, and better energy-efficiency compared to the GeForce 700 Series and GeForce 600 Series
Maxwell was announced in September 2010. The first GeForce consumer-class products based on the Maxwell architecture were released in early 2014. The Maxwell architecture is used in the system on a chip (SOC), mobile application processor, Tegra X1.
First generation Maxwell GM107/GM108 were released as GeForce GTX 745, GTX 750/750 Ti and GTX 850M/860M (GM107) and GT 830M/840M (GM108). These new chips provide few consumer-facing additional features; Nvidia instead focused on power efficiency. Nvidia increased the amount of L2 cache from 256 KiB on GK107 to 2 MiB on GM107, reducing the memory bandwidth needed. Accordingly, Nvidia cut the memory bus from 192 bit on GK106 to 128 bit on GM107, further saving power. Nvidia also changed the streaming multiprocessor design from that of Kepler (SMX), naming it SMM. The structure of the warp scheduler is inherited from Kepler, which allows each scheduler to issue up to two instructions that are independent from each other and are in order from the same warp. The layout of SMM units is partitioned so that each of the 4 warp schedulers in an SMM controls 1 set of 32 FP32 CUDA cores, 1 set of 8 load/store units, and 1 set of 8 special function units. This is in contrast to Kepler, where each SMX has 4 schedulers that schedule to a shared pool of 6 sets of 32 FP32 CUDA cores, 2 sets of 16 load/store units, and 2 sets of 16 special function units. These units are connected by a crossbar that uses power to allow the resources to be shared. This crossbar is removed in Maxwell. Texture units and FP64 CUDA cores are still shared. SMM allows for a finer-grain allocation of resources than SMX, saving power when the workload isn't optimal for shared resources. Nvidia claims a 128 CUDA core SMM has 86% of the performance of a 192 CUDA core SMX. Also, each Graphics Processing Cluster, or GPC, contains up to 4 SMX units in Kepler, and up to 5 SMM units in first generation Maxwell.