GeForce 8800 GT 512MB vs Radeon HD 6870

Intro

Compare that to the Radeon HD 6870, which comes with a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 memory running at 1050 MHz through a 256-bit bus. It also features 1120 SPUs, 56 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GT 512MB		105 Watts
Radeon HD 6870		151 Watts
	Difference: 46 Watts (44%)

Memory Bandwidth

As far as performance goes, the Radeon HD 6870 should theoretically be much better than the GeForce 8800 GT 512MB overall. (explain)

Radeon HD 6870		134400 MB/sec
GeForce 8800 GT 512MB		57600 MB/sec
	Difference: 76800 (133%)

Texel Rate

The Radeon HD 6870 is quite a bit (more or less 50%) faster with regards to anisotropic filtering than the GeForce 8800 GT 512MB. (explain)

Radeon HD 6870		50400 Mtexels/sec
GeForce 8800 GT 512MB		33600 Mtexels/sec
	Difference: 16800 (50%)

Pixel Rate

The Radeon HD 6870 will be quite a bit (approximately 200%) faster with regards to full screen anti-aliasing than the GeForce 8800 GT 512MB, and also capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6870		28800 Mpixels/sec
GeForce 8800 GT 512MB		9600 Mpixels/sec
	Difference: 19200 (200%)

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 data (measured in megabytes per second) that can be moved past the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. In the case of DDR memory, it must be multiplied by 2 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 AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at 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 card can possibly write 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 speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.