Comparison of GeForce GT 640M Mac and Radeon R7 250E

Attribute	Radeon R7 250E ×	GeForce GT 640M Mac ×
GPU
Release year (year)	2013	2013
Reference card	AMD Radeon R7 250E 800 MHz 1 GB	-
GPU brand	AMD	Nvidia
GPU name	Cape Verde	GK107
Market	Desktop	Laptop
Clock speed (MHz)	800	745
Is dual GPU	-	-
Model	Radeon R7 250E	GeForce GT 640M Mac
Memory
Memory (MB)	1,024	512
Memory bandwidth (GB/s)	72	40
Memory bus (bit)	128	64
Memory type	GDDR5	GDDR5
Memory clock speed (MHz)	1,125	1,250
Effective memory clock speed (MHz)	4,500	5,000
Noise and power
TDP (W)	55	32
Raw performance
Pixel rate (GPixel/s)	12.8	5.96
Render output processors	16	8
Texture mapping units	32	32
Shading units	512	384
Floating-point performance (GFLOPS)	819	572
Compute units	8	-
Texture rate (GTexel/s)	25.6	23.84
Benchmarks
Particle simulation (mInteraction/s)	-	69.88
T-Rex (Compubench 1.5) (frames/s)	-	0.56
Video composition (frames/s)	-	11.95
Cloud Gate Factor	12.88	-
Face detection (mPixels/s)	21.57	6.58
T-Rex (GFXBench 3.0)	3357.64	3356.32
Manhattan (GFXBench 3.0)	3602.72	2290.86
Bitcoin mining (mHash/s)	98.3	12.55
Sky Diver Factor	167.17	-
Fire Strike Factor	16.82	-
Ocean surface simulation (frames/s)	582.96	226.22