GeForce GT 640 vs GeForce GTX 660M

Find out if it is worth upgrading your current GPU setup by comparing GeForce GT 640 and GeForce GTX 660M. Here you can take a closer look at graphics cards specs, such as core clock speed, memory type and size, display connectors, etc. The price, overall benchmark and gaming performances are usually defining factors when it comes to choosing between GeForce GT 640 and GeForce GTX 660M. Make sure that the graphics card has compatible dimensions and will properly fit in your new or current computer case. Also these graphics cards may have different system power recommendations, so take that into consideration and upgrade your PSU if necessary.

GeForce GTX 660M is a Laptop Graphics Card

Note: GeForce GTX 660M is only used in laptop graphics. It has lower GPU clock speed compared to the desktop variant, which results in lower power consumption, but also 10-30% lower gaming performance. Check available laptop models with GeForce GTX 660M here:

Main Specs

  GeForce GT 640 GeForce GTX 660M
Power consumption (TDP) 65 Watt 50 Watt
Interface PCIe 3.0 x16 MXM-B (3.0)
Supplementary power connectors None
Memory type DDR3 GDDR5
Maximum RAM amount 2 GB 2 GB
Display Connectors 1x DVI, 1x HDMI, 1x DisplayPort No outputs
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  • GeForce GT 640 has 30% more power consumption, than GeForce GTX 660M.
  • GeForce GT 640 is connected by PCIe 3.0 x16, and GeForce GTX 660M uses MXM-B (3.0) interface.
  • GeForce GT 640 and GeForce GTX 660M have maximum RAM of 2 GB.
  • GeForce GT 640 is used in Desktops, and GeForce GTX 660M - in Laptops.
  • GeForce GT 640 and GeForce GTX 660M are build with Kepler architecture.
  • Core clock speed of GeForce GT 640 is 67 MHz higher, than GeForce GTX 660M.
  • GeForce GT 640 and GeForce GTX 660M are manufactured by 28 nm process technology.
  • Memory clock speed of GeForce GTX 660M is 218 MHz higher, than GeForce GT 640.

Game benchmarks

high / 1080p 2−3 6−7
ultra / 1080p 1−2 4−5
QHD / 1440p 0−1 0−1
low / 720p 14−16 16−18
medium / 1080p 5−6 8−9
The average gaming FPS of GeForce GTX 660M in Assassin's Creed Odyssey is 50% more, than GeForce GT 640.

Full Specs

  GeForce GT 640 GeForce GTX 660M
Architecture Kepler Kepler
Code name GK107 N13E-GE
Type Desktop Laptop
Release date 5 June 2012 22 March 2012
Pipelines 384 384
Core clock speed 902 MHz 835 MHz
Boost Clock 950 MHz
Transistor count 1,270 million 1,270 million
Manufacturing process technology 28 nm 28 nm
Texture fill rate 28.86 30.4 billion/sec
Floating-point performance 692.7 gflops 729.6 gflops
Length 145 mm
Memory bus width 128 Bit 128bit
Memory clock speed 1782 MHz 2000 MHz
Memory bandwidth 28.51 GB/s 64.0 GB/s
Shared memory -
DirectX 12 (11_0) 12 API
Shader Model 5.1 5.1
OpenGL 4.6 4.5
OpenCL 1.2 1.1
Vulkan 1.1.126 1.1.126
CUDA 3.0 +
CUDA cores 384
Bus support PCI Express 2.0, PCI Express 3.0
SLI options +
HDMI +
HDCP +
Maximum VGA resolution Up to 2048x1536
Bitcoin / BTC (SHA256) 24 Mh/s 36 Mh/s
Laptop size large
Optimus +
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