GeForce GT 640 DDR3 vs Radeon HD 6950 2GB

Intro

Compare that to the Radeon HD 6950 2GB, which makes use of a 40 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 memory runs at a frequency of 1250 MHz on this specific model. It features 1408 SPUs along with 88 Texture Address Units 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 HD 6950 2GB		200 Watts
	Difference: 135 Watts (208%)

Memory Bandwidth

The Radeon HD 6950 2GB, in theory, should be a lot faster than the GeForce GT 640 DDR3 in general. (explain)

Radeon HD 6950 2GB		160000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 102976 (181%)

Texel Rate

The Radeon HD 6950 2GB will be much (more or less 144%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)

Radeon HD 6950 2GB		70400 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 41600 (144%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 6950 2GB is superior to the GeForce GT 640 DDR3, and very much so. (explain)

Radeon HD 6950 2GB		25600 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 11200 (78%)

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 largest amount of data (counted in megabytes per second) that can be transported past the external memory interface in a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster 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 can be applied in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core clock speed. 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 of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.