GeForce GT 640 DDR3 vs Radeon R9 M295X

Intro

Compare those specifications to the Radeon R9 M295X, which has core clock speeds of 750 MHz on the GPU, and 1375 MHz on the 4096 MB of GDDR5 memory. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon R9 M295X		125 Watts
	Difference: 60 Watts (92%)

Memory Bandwidth

Performance-wise, the Radeon R9 M295X should theoretically be a lot better than the GeForce GT 640 DDR3 in general. (explain)

Radeon R9 M295X		176000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 118976 (209%)

Texel Rate

The Radeon R9 M295X is much (about 233%) better at texture filtering than the GeForce GT 640 DDR3. (explain)

Radeon R9 M295X		96000 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 67200 (233%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon R9 M295X is a better choice, and very much so. (explain)

Radeon R9 M295X		24000 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 9600 (67%)

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 (measured in MB per second) that can be transferred past the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better this number, the better the 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 maximum amount of pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.