NVIDIA GeForce GT 640M LE vs NVIDIA GeForce GT 650M

NVIDIA GeForce GT 640M LE

The NVIDIA GeForce GT 640M LE is a mid-range, DirectX 11.1 compatible graphics card that was announced in the first quarter of 2012 for thin-and-light-laptops. It is a Kepler-based GPU built on the GK107 architecture and is manufactured in 28nm at TSMC. The graphics card uses a 128-Bit wide memory interface with DDR3-VRAM. A slower core clock of only 500 MHz differs the LE-model from a normal GT 640M. Watch out: Following rumors, there will also be a Fermi-based version (96 shaders, 762 MHz, DDR3/GDDR5, similar to 550M/555M) with a probably higher power consumption than the Kepler variant.

Architecture

The Kepler architecture is the successor to the Fermi architecture that first appeared in laptops with the GeForce 500M 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.

Performance

Due to a clock speed of just 500 MHz, the gaming performance of the GeForce GT 640M LE is about 20 percent below the 640M. This is the same level as the GT 635M or the GT 555M. The performance is exceptionally good in shader-heavy DirectX 11 games and benchmarks. However, the 128-Bit memory interface can be a bottleneck if DDR3 graphics memory is used. Demanding games of 2011 like Battlefield 3 are playable in 1366x768 and medium settings.

Features

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 NVENC API.

The power consumption of the GeForce GT 640M LE is similar to the older GeForce GT 520M. As a result, the Nvidia GPU is suited for thin-and-light laptops.

NVIDIA GeForce GT 650M

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The NVIDIA GeForce GT 650M is a mid-range, DirectX 11.1 compatible graphics card that was announced in the first quarter of 2012 for laptops. It is a Kepler-based GPU built on the GK107 architecture and is 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. Due to a higher core clock of up to 850 MHz the GT 650M is noticably faster than the 640M.

Architecture

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 central 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 about as fast as one shader of a Fermi chip (as 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.

Performance

The gaming performance of the GeForce GT 650M equipped with DDR3 graphics memory is somewhere in the former 2011 high-end category between the GeForce GTX 460M and GTX 560M. The performance is exceptionally good in shader-heavy DirectX 11 games and benchmarks. However, the 128-Bit memory interface can be a bottleneck if DDR3 graphics memory is employed. Despite the slower core clock of only 735 MHz, the GDDR5-version of the card should be similar fast. Demanding games of 2011 like Battlefield 3 will be playable in 1366x768 and medium or high settings. Less demanding games, such as Modern Warfare 3, are easily playable with maxed out settings and 1080p resolution.

Features

The power consumption of the GeForce GT 650M should be best suited for medium-sized notebooks 15-inches or greater.

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NVIDIA GeForce GT 640M LE

NVIDIA GeForce GT 650M

GeForce GT 600M Series

GeForce GT 650M SLI	768 @ 0.79 - 0.84 GHz	2x 128 Bit @ 4000 MHz
GeForce GT 650M	384 @ 0.74 - 0.9 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 645M	384 @ 0.71 GHz	128 Bit @ 1800 MHz
GeForce GT 640M	384 @ 0.63 - 0.65 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 640M LE	384 @ 0.5 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 635M	144 @ 0.66 - 0.75 GHz	128/192 Bit @ 1800 MHz
GeForce GT 630M	96 @ 0.67 GHz	128 Bit @ 1800 MHz
GeForce GT 625M	96 @ 0.63 GHz	64 Bit @ 1800 MHz
GeForce GT 620M	96 @ 0.63 - 0.72 GHz	64 / 128 Bit @ 1800 MHz

GeForce GT 650M SLI	768 @ 0.79 - 0.84 GHz	2x 128 Bit @ 4000 MHz
GeForce GT 650M	384 @ 0.74 - 0.9 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 645M	384 @ 0.71 GHz	128 Bit @ 1800 MHz
GeForce GT 640M	384 @ 0.63 - 0.65 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 640M LE	384 @ 0.5 GHz	128 Bit @ 1800 - 4000 MHz
GeForce GT 635M	144 @ 0.66 - 0.75 GHz	128/192 Bit @ 1800 MHz
GeForce GT 630M	96 @ 0.67 GHz	128 Bit @ 1800 MHz
GeForce GT 625M	96 @ 0.63 GHz	64 Bit @ 1800 MHz
GeForce GT 620M	96 @ 0.63 - 0.72 GHz	64 / 128 Bit @ 1800 MHz

Codename

N13P-LP

N13E-GE

Architecture

Fermi / Kepler

Kepler

Pipelines

384 - unified

Core Speed

500 MHz

735 - 900 (Boost) MHz

Memory Speed

1800 - 4000 MHz

Memory Bus Width

128 Bit

Memory Type

DDR3, GDDR5

Max. Amount of Memory

2048 MB

Shared Memory

API

DirectX 11, Shader 5.0

technology

28 nm

Features

Optimus, PhysX, Verde Drivers, CUDA, 3D Vision, 3DTV Play

Notebook Size

medium sized

Date of Announcement

22.03.2012