GeForce GTX 660 vs Radeon HD 6990M Crossfire

If you are going to buy a new graphics card and are choosing between GeForce GTX 660 and Radeon HD 6990M Crossfire, 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 GTX 660 stacks up against Radeon HD 6990M Crossfire, check out specs charts below.

Radeon HD 6990M Crossfire is a Laptop Graphics Card

Note: Radeon HD 6990M Crossfire 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 Radeon HD 6990M Crossfire here:

Main Specs

  GeForce GTX 660 Radeon HD 6990M Crossfire
Power consumption (TDP) 140 Watt
Interface PCIe 3.0 x16
Supplementary power connectors One 6-pin
Memory type GDDR5 GDDR5
Maximum RAM amount 2 GB 2x2 GB
Display Connectors 2x DVI, 1x HDMI, 1x DisplayPort
  Check Price Check Price
  • GeForce GTX 660 and Radeon HD 6990M Crossfire have maximum RAM of 2 GB.
  • GeForce GTX 660 is used in Desktops, and Radeon HD 6990M Crossfire - in Laptops.
  • GeForce GTX 660 is build with Kepler architecture, and Radeon HD 6990M Crossfire - with Terascale 2.
  • Core clock speed of GeForce GTX 660 is 265 MHz higher, than Radeon HD 6990M Crossfire.
  • GeForce GTX 660 is manufactured by 28 nm process technology, and Radeon HD 6990M Crossfire - by 40 nm process technology.
  • Memory clock speed of Radeon HD 6990M Crossfire is 894 MHz higher, than GeForce GTX 660.

Game benchmarks

high / 1080p 20−22 35−40
ultra / 1080p 12−14 21−24
QHD / 1440p 6−7 16−18
4K / 2160p 5−6 10−11
low / 720p 40−45 60−65
medium / 1080p 24−27 40−45
The average gaming FPS of Radeon HD 6990M Crossfire in Assassin's Creed Odyssey is 68% more, than GeForce GTX 660.

Full Specs

  GeForce GTX 660 Radeon HD 6990M Crossfire
Architecture Kepler Terascale 2
Code name GK106 Blackcomb XTX
Type Desktop Laptop
Release date 6 September 2012 12 July 2011
Pipelines 960 2240
Core clock speed 980 MHz 715 MHz
Boost Clock 1033 MHz
Transistor count 2,540 million 2x1700 Million
Manufacturing process technology 28 nm 40 nm
Texture fill rate 78.4 billion/sec
Floating-point performance 1,981 gflops
Length 9.5" (24.1 cm)
Memory bus width 192-bit GDDR5 256 Bit
Memory clock speed 6.0 GB/s 900 MHz
Memory bandwidth 144.2 GB/s
Shared memory -
DirectX 12 (11_0) DirectX 11, Shader 5.0
Shader Model 5.1
OpenGL 4.3
OpenCL 1.2
Vulkan 1.1.126
CUDA +
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) 66 Mh/s
Laptop size large
  Check Price Check Price