GeForce GT 640 vs GeForce GTX 660

If you are going to buy a new graphics card and are choosing between GeForce GT 640 and GeForce GTX 660, there are a couple of things to consider. Cards with more VRAM in general perform better and allow you to play on higher graphics settings. Size also makes a difference. A model with a large heatsink can occupy up to three expansion slots on a motherboard. Be sure you have enough room in your PC case. When comparing GPUs with different architectures, more processing cores and even higher TFLOPS will not always translate to better performance. To help you decide which GPU you need, we have measured frame rates in a number of popular games. For more on how the GeForce GT 640 stacks up against GeForce GTX 660, check out specs charts below.

Main Specs

  GeForce GT 640 GeForce GTX 660
Power consumption (TDP) 65 Watt 140 Watt
Interface PCIe 3.0 x16 PCIe 3.0 x16
Supplementary power connectors None One 6-pin
Memory type DDR3 GDDR5
Maximum RAM amount 2 GB 2 GB
Display Connectors 1x DVI, 1x HDMI, 1x DisplayPort 2x DVI, 1x HDMI, 1x DisplayPort
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  • GeForce GTX 660 has 115% more power consumption, than GeForce GT 640.
  • Both video cards are using PCIe 3.0 x16 interface connection to a motherboard.
  • GeForce GT 640 and GeForce GTX 660 have maximum RAM of 2 GB.
  • Both cards are used in Desktops.
  • GeForce GT 640 and GeForce GTX 660 are build with Kepler architecture.
  • Core clock speed of GeForce GTX 660 is 78 MHz higher, than GeForce GT 640.
  • GeForce GT 640 and GeForce GTX 660 are manufactured by 28 nm process technology.
  • GeForce GT 640 is 136 mm longer, than GeForce GTX 660.
  • Memory clock speed of GeForce GT 640 is 1776 MHz higher, than GeForce GTX 660.

Game benchmarks

high / 1080p 2−3 20−22
ultra / 1080p 1−2 12−14
QHD / 1440p 0−1 6−7
4K / 2160p 5−6
low / 720p 14−16 40−45
medium / 1080p 5−6 24−27
The average gaming FPS of GeForce GTX 660 in Assassin's Creed Odyssey is 316% more, than GeForce GT 640.

Full Specs

  GeForce GT 640 GeForce GTX 660
Architecture Kepler Kepler
Code name GK107 GK106
Type Desktop Desktop
Release date 5 June 2012 6 September 2012
Pipelines 384 960
Core clock speed 902 MHz 980 MHz
Boost Clock 1033 MHz
Transistor count 1,270 million 2,540 million
Manufacturing process technology 28 nm 28 nm
Texture fill rate 28.86 78.4 billion/sec
Floating-point performance 692.7 gflops 1,981 gflops
Length 145 mm 9.5" (24.1 cm)
Memory bus width 128 Bit 192-bit GDDR5
Memory clock speed 1782 MHz 6.0 GB/s
Memory bandwidth 28.51 GB/s 144.2 GB/s
DirectX 12 (11_0) 12 (11_0)
Shader Model 5.1 5.1
OpenGL 4.6 4.3
OpenCL 1.2 1.2
Vulkan 1.1.126 1.1.126
CUDA 3.0 +
CUDA cores 960
Bus support PCI Express 3.0
Height 4.376" (11.1 cm)
SLI options +
Multi monitor support 4 displays
HDMI +
HDCP +
Maximum VGA resolution 2048x1536
Audio input for HDMI Internal
3D Blu-Ray +
3D Gaming +
3D Vision +
Bitcoin / BTC (SHA256) 24 Mh/s 66 Mh/s
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