GeForce 840M and GeForce GT 420 OEM - video card comparison
GeForce 840M
GeForce GT 420 OEM
Architecture
Maxwell (2014−2018)
Fermi (2010−2014)
GPU code name
N15S-GT
GF108
Market segment
Laptop
Desktop
Release date
March 2014
September 2010
Bus support
PCI Express 2.0, PCI Express 3.0
-
Interface
PCIe 3.0 x8
PCIe 2.0 x16
Supplementary power connectors
-
None
Boost clock speed
1124 MHz
-
Core clock speed
1029 MHz
700 MHz
Floating-point performance
863.2 gflops
134.4 gflops
Manufacturing process technology
28 nm
40 nm
Number of transistors
-
585 million
Pipelines / CUDA cores
384
48
Power consumption (TDP)
33 Watt
50 Watt
Texture fill rate
17.98
2.800
Memory type
DDR3
DDR3
Maximum RAM amount
4 GB
1 GB
Memory bus width
64 Bit
128 Bit
Memory clock speed
2000 MHz
1800 MHz
Memory bandwidth
16.02 GB/s
28.8 GB/s
Shared memory
-
-
Display Connectors
No outputs
1x DVI, 1x HDMI, 1x VGA
HDMI
-
+
DirectX
12 (11_0)
12 (11_0)
CUDA
+
2.1
OpenCL
1.2
1.1
OpenGL
4.5
4.6
Shader Model
5.1
5.1
Vulkan
1.1.126
N/A
GameWorks
+
-
GPU Boost
2.0
-
Optimus
+
-