GeForce GT 640 DDR3 vs Radeon R9 M395X

Intro

Compare all of that to the Radeon R9 M395X, which has core speeds of 723 MHz on the GPU, and 1250 MHz on the 4096 MB of GDDR5 memory. It features 2048 SPUs as well as 128 TAUs and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon R9 M395X		125 Watts
	Difference: 60 Watts (92%)

Memory Bandwidth

The Radeon R9 M395X should in theory perform much faster than the GeForce GT 640 DDR3 overall. (explain)

Radeon R9 M395X		160000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 102976 (181%)

Texel Rate

The Radeon R9 M395X will be quite a bit (approximately 221%) more effective at AF than the GeForce GT 640 DDR3. (explain)

Radeon R9 M395X		92544 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 63744 (221%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon R9 M395X is the winner, by a large margin. (explain)

Radeon R9 M395X		23136 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 8736 (61%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the bus width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.