GeForce 840A and GeForce GT 645 OEM - video card comparison
GeForce 840A
GeForce GT 645 OEM
Architecture
Maxwell (2014−2018)
Fermi 2.0 (2010−2014)
GPU code name
GM108
GF114
Market segment
Desktop
Desktop
Release date
March 2014
April 2012
Interface
PCIe 3.0 x8
PCIe 2.0 x16
Boost clock speed
1124 MHz
-
Core clock speed
1029 MHz
776 MHz
Floating-point performance
863.2 gflops
894.0 gflops
Manufacturing process technology
28 nm
40 nm
Number of transistors
-
1,950 million
Pipelines / CUDA cores
384
288
Power consumption (TDP)
33 Watt
102 Watt
Texture fill rate
17.98
37.25
Memory type
DDR3
GDDR5
Maximum RAM amount
2 GB
1 GB
Memory bus width
64 Bit
192 Bit
Memory clock speed
2002 MHz
3828 MHz
Memory bandwidth
16.02 GB/s
91.87 GB/s
Display Connectors
No outputs
2x DVI, 1x mini-HDMI
HDMI
-
+
DirectX
12 (11_0)
12 (11_0)
CUDA
5.0
2.1
OpenCL
1.2
1.1
OpenGL
4.6
4.6
Shader Model
5.1
5.1
Vulkan
1.1.126
N/A