GeForce 840A vs GeForce GT 640M

Find out if it is worth upgrading your current GPU setup by comparing GeForce 840A and GeForce GT 640M. 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 840A and GeForce GT 640M. 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 GT 640M is a Laptop Graphics Card

Note: GeForce GT 640M 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 GT 640M here:

Main Specs

  GeForce 840A GeForce GT 640M
Power consumption (TDP) 33 Watt 32 Watt
Interface PCIe 3.0 x8 PCIe 3.0 x16
Memory type DDR3 DDR3\GDDR5
Maximum RAM amount 2 GB 2 GB
Display Connectors No outputs No outputs
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  • GeForce 840A has 3% more power consumption, than GeForce GT 640M.
  • GeForce 840A is connected by PCIe 3.0 x8, and GeForce GT 640M uses PCIe 3.0 x16 interface.
  • GeForce 840A and GeForce GT 640M have maximum RAM of 2 GB.
  • GeForce 840A is used in Desktops, and GeForce GT 640M - in Laptops.
  • GeForce 840A is build with Maxwell architecture, and GeForce GT 640M - with Kepler.
  • GeForce 840A and GeForce GT 640M are manufactured by 28 nm process technology.
  • Memory clock speed of GeForce 840A is 202 MHz higher, than GeForce GT 640M.

Game benchmarks

high / 1080p 3−4 0−1
ultra / 1080p 2−3 0−1
QHD / 1440p 0−1 0−1
low / 720p 14−16 10−12
medium / 1080p 5−6 2−3
The average gaming FPS of GeForce 840A in Assassin's Creed Odyssey is 66% more, than GeForce GT 640M.

Full Specs

  GeForce 840A GeForce GT 640M
Architecture Maxwell Kepler
Code name GM108 N13P-GS
Type Desktop Laptop
Release date 17 March 2014 22 March 2012
Pipelines 384 384
Core clock speed 1029 MHz
Boost Clock 1124 MHz 645 MHz
Transistor count 1,270 million
Manufacturing process technology 28 nm 28 nm
Texture fill rate 17.98
Floating-point performance 863.2 gflops 480.0 gflops
Memory bus width 64 Bit 128bit
Memory clock speed 2002 MHz 1800 - 4000 MHz
Memory bandwidth 16.02 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 5.0 +
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
Optimus +
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