GeForce GTX 970

Written by Boldson on 30 April 2017. Posted in GeForce GTX 9XX Series

nvidia geforce gtx 970

Along with the flagship gaming video adapter based on the Maxwell architecture, the younger model with the same GPU - GM204, which has lower frequencies and partially blocked computing units, also saw the light of day.

GeForce GTX 970 and GTX 980 differ primarily in the number of active computing units of the GM204 chip. The dies allocated to the GTX 970 have 3 out of 16 MMX disabled. Consequently, out of 2048 CUDA cores and 128 texture units, only 1664 and 104, respectively, remained in service. The differences in GPU front-end configuration are significant. In addition, the GTX 970 has reduced clock speeds: from 1126/1216 to 1050/1178 (base clock and Boost Clock, respectively).

sm.gm204 cut.600

But the back-end of the processor was not affected. 64 ROPs and four 64-bit memory controllers are still active. The effective frequency of RAM according to the reference specifications is 7 GHz, the volume is 4 GB.

The launch of the GeForce GTX 970 is not accompanied by the release of a reference device - NVIDIA has outsourced the design directly to video card manufacturers.

Specifications GeForce GTX 970

date of release	September 19, 2014
Starting price, $	329

Chip

GPU model	28nm GM204-200
Cores: TMUs : ROPs	1664:104:56

Frequencies

GPU(boost) frequency, MHz	1051(1178)
Memory frequency (effective), MHz	1750 (7000)
Performance FP32, GFLOPS	3.498

Memory

Video memory size, MB	3584(4096)
Memory bus, bit	256
Memory bandwidth, GB/s	192

Interface and TDP

PCI-Express Interface	3.0x16
TDP. Tue	145

The GeForce GTX 970 essentially has only 3.5 GB of main video memory. The reason lies in the different ways in which SMM (Maxwell Streaming Multiprocessors) are implemented. A GeForce GTX 980 or GPU GM204 uses four GPCs (Graphics Processing Clusters) x 4 SMMs x 4 SMMs x 32 ALUs, resulting in 2,048 stream processors. With the GeForce GTX 970 we get 13 SMMs x SMMs x 32 ALUs = 1.664 stream processors. Missing SMMs result in corresponding "gaps" in the GPU's memory subsystem.

GTX970 GM204 crossbar rs

As a result, only 3.5 GB of memory out of 4 GB are addressed at full speed. In particular, NVIDIA uses two sections of memory: 512 MB and 3.584 MB. If a game requires 3.5 GB of memory or less, then it can only use the first partition. If more than 3.5 GB is required, then the GeForce GTX 970 uses both partitions, but no longer at full speed, so we get a difference in memory performance between the GTX 970 and GTX 980, which is not related to the difference in the number of texture units and stream processors.