GeForce 840M and GeForce GTX 680MX Mac Edition - video card comparison
GeForce 840M
GeForce GTX 680MX Mac Edition
Architecture
Maxwell (2014−2018)
Kepler (2012−2018)
GPU code name
N15S-GT
GK104
Market segment
Laptop
Desktop
Release date
March 2014
October 2012
Bus support
PCI Express 2.0, PCI Express 3.0
-
Interface
PCIe 3.0 x8
PCIe 3.0 x16
Boost clock speed
1124 MHz
-
Core clock speed
1029 MHz
719 MHz
Floating-point performance
863.2 gflops
2,209 gflops
Manufacturing process technology
28 nm
28 nm
Number of transistors
-
3,540 million
Pipelines / CUDA cores
384
1536
Power consumption (TDP)
33 Watt
122 Watt
Texture fill rate
17.98
92.03
Memory type
DDR3
GDDR5
Maximum RAM amount
4 GB
2 GB
Memory bus width
64 Bit
256 Bit
Memory clock speed
2000 MHz
5000 MHz
Memory bandwidth
16.02 GB/s
160.0 GB/s
Shared memory
-
-
Display Connectors
No outputs
No outputs
DirectX
12 (11_0)
12 (11_0)
CUDA
+
3.0
OpenCL
1.2
1.2
OpenGL
4.5
4.6
Shader Model
5.1
5.1
Vulkan
1.1.126
1.1.126
GameWorks
+
-
GPU Boost
2.0
-
Optimus
+
-