GeForce GTX 660 and GeForce GT 645 OEM - video card comparison
GeForce GTX 660
GeForce GT 645 OEM
Architecture
Kepler (2012−2018)
Fermi 2.0 (2010−2014)
GPU code name
GK106
GF114
Market segment
Desktop
Desktop
Release date
September 2012
April 2012
Bus support
PCI Express 3.0
-
Interface
PCIe 3.0 x16
PCIe 2.0 x16
Supplementary power connectors
One 6-pin
-
SLI options
+
-
Boost clock speed
1033 MHz
-
Core clock speed
980 MHz
776 MHz
CUDA cores
960
-
Floating-point performance
1,981 gflops
894.0 gflops
Manufacturing process technology
28 nm
40 nm
Number of transistors
2,540 million
1,950 million
Pipelines / CUDA cores
960
288
Power consumption (TDP)
140 Watt
102 Watt
Texture fill rate
78.4 billion/sec
37.25
Memory type
GDDR5
GDDR5
Maximum RAM amount
2 GB
1 GB
Memory bus width
192-bit GDDR5
192 Bit
Memory clock speed
6.0 GB/s
3828 MHz
Memory bandwidth
144.2 GB/s
91.87 GB/s
Display Connectors
One Dual Link DVI-I, One Dual Link DVI-D, One HDMI, One DisplayPort
2x DVI, 1x mini-HDMI
Multi monitor support
4 displays
-
HDMI
+
+
HDCP
+
-
Maximum VGA resolution
2048x1536
-
Audio input for HDMI
Internal
-
DirectX
12 (11_0)
12 (11_0)
CUDA
+
2.1
OpenCL
1.2
1.1
OpenGL
4.3
4.6
Shader Model
5.1
5.1
Vulkan
1.1.126
N/A
3D Blu-Ray
+
-
3D Gaming
+
-
3D Vision
+
-