GeForce 840M and GeForce GT 640M - video card comparison
Passmark - benchmark score GeForce 840M vs GeForce GT 640M
GeForce 840M
1121
GeForce GT 640M
943
GeForce 840M
GeForce GT 640M
Architecture
Maxwell (2014−2018)
Kepler (2012−2018)
GPU code name
N15S-GT
N13P-GS
Market segment
Laptop
Laptop
Release date
March 2014
March 2012
Bus support
PCI Express 2.0, PCI Express 3.0
PCI Express 2.0, PCI Express 3.0
Interface
PCIe 3.0 x8
PCIe 3.0 x16
Boost clock speed
1124 MHz
645 MHz
Core clock speed
1029 MHz
Up to 625 MHz
CUDA cores
-
384
Floating-point performance
863.2 gflops
480.0 gflops
Manufacturing process technology
28 nm
28 nm
Number of transistors
-
1,270 million
Pipelines / CUDA cores
384
384
Power consumption (TDP)
33 Watt
32 Watt
Texture fill rate
17.98
Up to 20.0 billion/sec
Memory type
DDR3
DDR3\GDDR5
Maximum RAM amount
4 GB
2 GB
Memory bus width
64 Bit
128bit
Memory clock speed
2000 MHz
1800 - 4000 MHz
Memory bandwidth
16.02 GB/s
Up to 64.0 GB/s
Shared memory
-
-
Display Connectors
No outputs
No outputs
HDMI
-
+
HDCP
-
+
Maximum VGA resolution
-
Up to 2048x1536
DirectX
12 (11_0)
12 API
CUDA
+
+
OpenCL
1.2
1.1
OpenGL
4.5
4.5
Shader Model
5.1
5.1
Vulkan
1.1.126
1.1.126
3D Blu-Ray
-
+
GameWorks
+
-
GPU Boost
2.0
-
Optimus
+
+