Radeon HD 6870 X2 and GeForce GTX 660 OEM - video card comparison
Radeon HD 6870 X2
GeForce GTX 660 OEM
Architecture
TeraScale 2 (2009−2015)
Kepler (2012−2018)
GPU code name
Barts
GK104
Market segment
Desktop
Desktop
Release date
July 2011
August 2012
Interface
PCIe 2.0 x16
PCIe 3.0 x16
Supplementary power connectors
-
1x 6-pin
Boost clock speed
-
888 MHz
Core clock speed
900 MHz
823 MHz
Floating-point performance
2x 2,016.0 gflops
2,046 gflops
Manufacturing process technology
40 nm
28 nm
Number of transistors
1,700 million
3,540 million
Pipelines / CUDA cores
1120
1152
Power consumption (TDP)
300 Watt
130 Watt
Texture fill rate
50.40
85.25
Memory type
GDDR5
GDDR5
Maximum RAM amount
1 GB
2 GB
Memory bus width
256 Bit
256 Bit
Memory clock speed
4200 MHz
5600 MHz
Memory bandwidth
134.4 GB/s
179.2 GB/s
Display Connectors
2x DVI, 1x HDMI, 2x mini-DisplayPort
2x DVI, 1x HDMI, 1x DisplayPort
HDMI
+
+
DirectX
11.2 (11_0)
12 (11_0)
CUDA
-
3.0
OpenCL
1.2
1.2
OpenGL
4.4
4.6
Shader Model
5.0
5.1
Vulkan
N/A
1.1.126