GeForce GT 645M vs Radeon HD 8790M

If you are going to buy a new graphics card and are choosing between GeForce GT 645M and Radeon HD 8790M, 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 645M stacks up against Radeon HD 8790M, check out specs charts below.

GeForce GT 645M and Radeon HD 8790M are Laptop Graphics Cards

Note: GeForce GT 645M and Radeon HD 8790M 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 645M or Radeon HD 8790M here:

Main Specs

  GeForce GT 645M Radeon HD 8790M
Power consumption (TDP) 32 Watt
Interface PCIe 3.0 x16 MXM-A (3.0)
Supplementary power connectors None
Memory type DDR3\GDDR5 GDDR5
Maximum RAM amount 2 GB 2 GB
Display Connectors No outputs No outputs
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  • GeForce GT 645M is connected by PCIe 3.0 x16, and Radeon HD 8790M uses MXM-A (3.0) interface.
  • GeForce GT 645M and Radeon HD 8790M have maximum RAM of 2 GB.
  • Both cards are used in Laptops.
  • GeForce GT 645M is build with Kepler architecture, and Radeon HD 8790M - with GCN.
  • GeForce GT 645M and Radeon HD 8790M are manufactured by 28 nm process technology.
  • Memory clock speed of Radeon HD 8790M is 2700 MHz higher, than GeForce GT 645M.

Game benchmarks

high / 1080p 1−2 3−4
ultra / 1080p 0−1 1−2
QHD / 1440p 0−1 0−1
low / 720p 12−14 14−16
medium / 1080p 2−3 6−7
The average gaming FPS of Radeon HD 8790M in Assassin's Creed Odyssey is 60% more, than GeForce GT 645M.

Full Specs

  GeForce GT 645M Radeon HD 8790M
Architecture Kepler GCN
Code name N13P-GS Mars XTX
Type Laptop Laptop
Release date 22 March 2012 16 November 2012
Pipelines 384 384
Core clock speed 850 MHz
Boost Clock 900 MHz
Transistor count 1,270 million 950 million
Manufacturing process technology 28 nm 28 nm
Texture fill rate 22.7 billion/sec 21.60
Floating-point performance 544.5 gflops 691.2 gflops
Memory bus width 128bit 128 Bit
Memory clock speed 1800 MHz 4500 MHz
Memory bandwidth 64 GB/s
Shared memory - -
DirectX 12 API 12 (11_1)
Shader Model 5.1 5.1
OpenGL 4.5 4.6
OpenCL 1.1 1.2
Vulkan 1.1.126 1.2.131
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) 19 Mh/s 80 Mh/s
Laptop size medium sized medium sized
Optimus +
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