NVIDIA GeForce GT 645M

NVIDIA GeForce GT 645M

The NVIDIA GeForce GT 645M is a mid-range, DirectX 11.1 compatible graphics card that was announced in the third quarter of 2012 for laptops. It is a faster clocked GeForce GT 640M and therefore also based on the Kepler GK107 architecture manufactured in 28nm at TSMC. The graphics card uses a 128-Bit wide memory interface with either the more common but slower DDR3 for VRAM or the more expensive and faster GDDR5.


The Kepler architecture is the successor to the Fermi architecture that first appeared in laptops with the GeForce 400M series. The GK107 Kepler core offers two shader blocks, called SMX, each with 192 shaders for a total of 384 shader cores that are clocked at the same speed as the processor core. Although more shader cores are available in the Kepler architecture as compared to the Fermi design, the Kepler shaders are still expected to be up to twice as power efficient. However, due to the missing hot clock of the shader domain, two shaders of a Kepler chip are as fast as one shader of a Fermi chip (the latter is clocked twice as fast). PCIe 3.0 is now supported by the mobile Kepler series and an optional Turbo mode can automatically overclock the Nvidia card by a theoretical 15 percent if the laptop cooling system allows it. The implementation of this boost mode is done in the BIOS, but it is ultimately dependent upon the manufacturer of the laptop.


The gaming performance of the GeForce GT 645M equipped with DDR3 graphics memory depends on the 3D clock in the used laptop and is slightly above an average GT 640M. Therefore demanding games like Battlefield 3 are playable in 1366x768 and medium settings. Older and less demanding games, such as Modern Warfare 3, are easily playable with maxed out settings and high resolutions.


The improved feature set now includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840x2160 pixels can now be connected using DisplayPort 1.2 or HDMI 1.4a if available. HD-Audio codecs, such as Dolby TrueHD and DTS-HD, can be transmitted via bitstream mode through the HDMI port. However, as most laptops will feature Optimus, the integrated GPU will likely have direct control over the display ports and may limit the feature set available by the Nvidia Kepler cards.

The 5th generation PureVideo HD video processor (VP5) is also integrated in the GK107 core and offers hardware decoding of HD videos. Common codecs such as MPEG-1/2, MPEG-4 ASP, H.264 and VC1/WMV9 are fully supported up to 4K resolutions while VC1 and MPEG-4 are supported up to 1080p. Two streams can be decoded in parallel for features such as Picture-in-Picture. Another novelty is the inclusion of a dedicated video encoding engine similar to Intel QuickSync that can be accessed by the NVENCI API.

The power consumption of the GeForce GT 645M should be similar to the GT 640M and therefore a bit below that of the older GeForce GT 540M and more in line with the GT 525M. As a result, the Nvidia GPU is best suited for multimedia notebooks 14-inches or greater.

GeForce GT 600M Series
GeForce GT 650M SLI (compare) 768 @ 790 - 835 (Boost) MHz2x 128 Bit @ 4000 MHz
GeForce GT 650M (compare) 384 @ 735 - 900 (Boost) MHz128 Bit @ 1800 - 4000 MHz
GeForce GT 645M 384 @ 710 MHz128 Bit @ 1800 MHz
GeForce GT 640M (compare) 384 @ 625 - 645 (Boost) MHz128 Bit @ 1800 - 4000 MHz
GeForce GT 640M LE (compare) 384 @ 500 MHz128 Bit @ 1800 - 4000 MHz
GeForce GT 635M (compare) 144 @ 660 - 753 (Boost) MHz128/192 Bit @ 1800 MHz
GeForce GT 630M (compare) 96 @ 672 MHz128 Bit @ 1800 MHz
GeForce GT 625M (compare) 96 @ 625 MHz64 Bit @ 1800 MHz
GeForce GT 620M (compare) 96 @ 625 - 715 (Boost) MHz64 / 128 Bit @ 1800 MHz
Pipelines384 - unified
Core Speed710 MHz
Memory Speed1800 MHz
Memory Bus Width128 Bit
Memory TypeDDR3
Max. Amount of Memory2048 MB
Shared Memoryno
DirectXDirectX 11, Shader 5.0
technology28 nm
FeaturesOptimus, PhysX, Verde Drivers, CUDA, 3D Vision, 3DTV Play
Notebook Sizemedium sized
Date of Announcement22.03.2012
Link to Manufacturer Page


3DMark - Cloud Gate Standard Score 1280x720
min: 5466     avg: 6537     median: 6537 (11%)     max: 7608 Points
3DMark - Cloud Gate Standard Graphics 1280x720
min: 8483     avg: 8654.5     median: 8654 (5%)     max: 8826 Points
3DMark - Fire Strike Score 1920x1080
min: 1106     avg: 1146.5     median: 1146 (4%)     max: 1187 Points
3DMark - Fire Strike Graphics 1920x1080
min: 1126     avg: 1151.5     median: 1151 (3%)     max: 1177 Points
3DMark - Ice Storm Standard Graphics 1280x720
min: 72143     avg: 74439     median: 74439 (10%)     max: 76735 Points
3DMark 11 - Performance 1280x720
min: 1853     avg: 1976.3     median: 1962 (6%)     max: 2127 points
3DMark 11 - Performance GPU 1280x720
min: 1753     avg: 1845.8     median: 1844 (4%)     max: 1941 points
3DMark Vantage
P Result 1280x1024 +
P GPU no PhysX 1280x1024 +
3DMark 06 Standard 1280x1024 +
Unigine Heaven 3.0 - DX 11, Normal Tessellation, High Shaders 1920x1080
min: 16     avg: 17.7     median: 17 (6%)     max: 18 fps
Unigine Heaven 2.1 - high, Tesselation (normal), DirectX11 1280x1024
min: 21     avg: 23.4     median: 23 (10%)     max: 24 fps
SPECviewperf 11
Siemens NX 1920x1080 +
Tcvis 1920x1080 +
SolidWorks 1920x1080 +
Pro/ENGINEER 1920x1080 +
Maya 1920x1080 +
Lightwave 1920x1080 +
Ensight 1920x1080 +
Catia 1920x1080 +
Cinebench R10 Shading 32Bit +
Cinebench R11.5 OpenGL 64Bit +
- Range of benchmark values for this graphics card
- Average benchmark values for this graphics card
* Smaller numbers mean a higher performance

Game Benchmarks

The following benchmarks stem from our benchmarks of review laptops. The performance depends on the used graphics memory, clock rate, processor, system settings, drivers, and operating systems. So the results don't have to be representative for all laptops with this GPU. For detailed information on the benchmark results, click on the fps number.

low 1280x720
83.9  fps    + Compare
med. 1366x768
46.9  fps    + Compare
high 1366x768
40.3  fps    + Compare
ultra 1920x1080
14.3  fps    + Compare
» With all tested laptops playable in detail settings high.
low 1024x768
207.6  fps    + Compare
med. 1366x768
69.6  fps    + Compare
high 1366x768
47.7  fps    + Compare
ultra 1920x1080
17.7  fps    + Compare
» With all tested laptops playable in detail settings high.


low 1024x768
46  fps    + Compare
med. 1366x768
24  fps    + Compare
high 1366x768
19.4  fps    + Compare
ultra 1920x1080
11.7  fps    + Compare
» With all tested laptops playable in detail settings low.
low 1024x768
97.2  fps    + Compare
med. 1366x768
52.7  fps    + Compare
high 1366x768
34.2  fps    + Compare
ultra 1920x1080
13.1  fps    + Compare
» With all tested laptops playable in detail settings med..
Crysis 3

Crysis 3

low 1024x768
46.6  fps    + Compare
med. 1366x768
27.6  fps    + Compare
high 1366x768
18.6  fps    + Compare
ultra 1920x1080
7  fps    + Compare