GeForce GT 640 DDR3 vs Radeon HD 6750

Intro

Compare those specifications to the Radeon HD 6750, which features GPU clock speed of 725 MHz, and 512 MB of GDDR5 RAM running at 1000 MHz through a 128-bit bus. It also features 720 Stream Processors, 36 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
Radeon HD 6750		86 Watts
	Difference: 21 Watts (32%)

Memory Bandwidth

In theory, the Radeon HD 6750 is 12% quicker than the GeForce GT 640 DDR3 in general, because of its higher bandwidth. (explain)

Radeon HD 6750		64000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 6976 (12%)

Texel Rate

The GeForce GT 640 DDR3 should be a small bit (about 10%) more effective at anisotropic filtering than the Radeon HD 6750. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
Radeon HD 6750		26100 Mtexels/sec
	Difference: 2700 (10%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce GT 640 DDR3 is superior to the Radeon HD 6750, by a large margin. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
Radeon HD 6750		11600 Mpixels/sec
	Difference: 2800 (24%)

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 transferred over the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.