GeForce GT 640 DDR3 vs Radeon R9 M290X

Intro

Compare those specifications to the Radeon R9 M290X, which uses a 28 nm design. AMD has set the core frequency at 850 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this card. It features 1280 SPUs as well as 80 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 M290X		100 Watts
	Difference: 35 Watts (54%)

Memory Bandwidth

In theory, the Radeon R9 M290X is 169% faster than the GeForce GT 640 DDR3 in general, due to its higher data rate. (explain)

Radeon R9 M290X		153600 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 96576 (169%)

Texel Rate

The Radeon R9 M290X will be quite a bit (approximately 136%) faster with regards to anisotropic filtering than the GeForce GT 640 DDR3. (explain)

Radeon R9 M290X		68000 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 39200 (136%)

Pixel Rate

The Radeon R9 M290X should be quite a bit (about 89%) more effective at anti-aliasing than the GeForce GT 640 DDR3, and also able to handle higher resolutions without losing too much performance. (explain)

Radeon R9 M290X		27200 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 12800 (89%)

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: Bandwidth is the max amount of data (measured in MB per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, 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 number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

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