GeForce 8800 GT 512MB vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which has a core clock frequency of 830 MHz and a GDDR5 memory speed of 1250 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It features 1536 SPUs, 96 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 6990		375 Watts
	Difference: 270 Watts (257%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6990 should be much faster than the GeForce 8800 GT 512MB in general. (explain)

Radeon HD 6990		320000 MB/sec
GeForce 8800 GT 512MB		57600 MB/sec
	Difference: 262400 (456%)

Texel Rate

The Radeon HD 6990 will be a lot (more or less 374%) better at anisotropic filtering than the GeForce 8800 GT 512MB. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce 8800 GT 512MB		33600 Mtexels/sec
	Difference: 125760 (374%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 6990 is the winner, and very much so. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce 8800 GT 512MB		9600 Mpixels/sec
	Difference: 43520 (453%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of data (in units of megabytes per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.