GeForce GT 640M vs Radeon HD 6990M Crossfire

When comparing GeForce GT 640M and Radeon HD 6990M Crossfire, we look primarily at benchmarks and game tests. But it is not only about the numbers. Often you can find third-party models with higher clock speeds, better cooling, or a customizable RGB lighting. Not all of them will have all the features you need. Another thing to consider is the port selection. Most graphics cards have at least one DisplayPort and HDMI interface, but some monitors require DVI. Before you buy, check the TDP of the graphics card - this characteristic will help you estimate the consumption of the graphics card. You may even have to upgrade your PSU to meet its requirements. An important factor when choosing between GeForce GT 640M and Radeon HD 6990M Crossfire is the price. Does the additional cost justify the performance hit? Our comparison should help you make the right decision.

GeForce GT 640M and Radeon HD 6990M Crossfire are Laptop Graphics Cards

Note: GeForce GT 640M and Radeon HD 6990M Crossfire are only used in laptop graphics. They have 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 GT 640M or Radeon HD 6990M Crossfire here:

Main Specs

  GeForce GT 640M Radeon HD 6990M Crossfire
Power consumption (TDP) 32 Watt
Interface PCIe 3.0 x16
Memory type DDR3\GDDR5 GDDR5
Maximum RAM amount 2 GB 2x2 GB
Display Connectors No outputs
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  • GeForce GT 640M and Radeon HD 6990M Crossfire have maximum RAM of 2 GB.
  • Both cards are used in Laptops.
  • GeForce GT 640M is build with Kepler architecture, and Radeon HD 6990M Crossfire - with Terascale 2.
  • GeForce GT 640M is manufactured by 28 nm process technology, and Radeon HD 6990M Crossfire - by 40 nm process technology.
  • Memory clock speed of GeForce GT 640M is 900 MHz higher, than Radeon HD 6990M Crossfire.

Game benchmarks

high / 1080p 0−1 35−40
ultra / 1080p 0−1 21−24
QHD / 1440p 0−1 16−18
4K / 2160p 10−11
low / 720p 10−12 60−65
medium / 1080p 2−3 40−45
The average gaming FPS of Radeon HD 6990M Crossfire in Assassin's Creed Odyssey is 766% more, than GeForce GT 640M.

Full Specs

  GeForce GT 640M Radeon HD 6990M Crossfire
Architecture Kepler Terascale 2
Code name N13P-GS Blackcomb XTX
Type Laptop Laptop
Release date 22 March 2012 12 July 2011
Pipelines 384 2240
Core clock speed 715 MHz
Boost Clock 645 MHz
Transistor count 1,270 million 2x1700 Million
Manufacturing process technology 28 nm 40 nm
Floating-point performance 480.0 gflops
Memory bus width 128bit 256 Bit
Memory clock speed 1800 - 4000 MHz 900 MHz
Shared memory - -
DirectX 12 API DirectX 11, Shader 5.0
Shader Model 5.1
OpenGL 4.5
OpenCL 1.1
Vulkan 1.1.126
CUDA +
CUDA cores 384
Bus support PCI Express 2.0, PCI Express 3.0
HDMI +
HDCP +
Maximum VGA resolution Up to 2048x1536
3D Blu-Ray +
Bitcoin / BTC (SHA256) 18 Mh/s
Laptop size medium sized large
Optimus +
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